Chapter 4. Configuring persistent storage 4.1. Persistent storage using AWS Elastic Block Store OpenShift Container Platform supports Amazon Elastic Block Store (EBS) volumes. You can provision your OpenShift Container Platform cluster with persistent storage by using Amazon EC2 . The Kubernetes persistent volume framework allows administrators to provision a cluster with persistent storage and gives users a way to request those resources without having any knowledge of the underlying infrastructure. You can dynamically provision Amazon EBS volumes. Persistent volumes are not bound to a single project or namespace; they can be shared across the OpenShift Container Platform cluster. Persistent volume claims are specific to a project or namespace and can be requested by users. You can define a KMS key to encrypt container-persistent volumes on AWS. By default, newly created clusters using OpenShift Container Platform version 4.10 and later use gp3 storage and the AWS EBS CSI driver . Important High-availability of storage in the infrastructure is left to the underlying storage provider. Important OpenShift Container Platform 4.12 and later provides automatic migration for the AWS Block in-tree volume plugin to its equivalent CSI driver. CSI automatic migration should be seamless. Migration does not change how you use all existing API objects, such as persistent volumes, persistent volume claims, and storage classes. For more information about migration, see CSI automatic migration . 4.1.1. Creating the EBS storage class Storage classes are used to differentiate and delineate storage levels and usages. By defining a storage class, users can obtain dynamically provisioned persistent volumes. 4.1.2. Creating the persistent volume claim Prerequisites Storage must exist in the underlying infrastructure before it can be mounted as a volume in OpenShift Container Platform. Procedure In the OpenShift Container Platform console, click Storage Persistent Volume Claims . In the persistent volume claims overview, click Create Persistent Volume Claim . Define the desired options on the page that appears. Select the previously-created storage class from the drop-down menu. Enter a unique name for the storage claim. Select the access mode. This selection determines the read and write access for the storage claim. Define the size of the storage claim. Click Create to create the persistent volume claim and generate a persistent volume. 4.1.3. Volume format Before OpenShift Container Platform mounts the volume and passes it to a container, it checks that the volume contains a file system as specified by the fsType parameter in the persistent volume definition. If the device is not formatted with the file system, all data from the device is erased and the device is automatically formatted with the given file system. This verification enables you to use unformatted AWS volumes as persistent volumes, because OpenShift Container Platform formats them before the first use. 4.1.4. Maximum number of EBS volumes on a node By default, OpenShift Container Platform supports a maximum of 39 EBS volumes attached to one node. This limit is consistent with the AWS volume limits . The volume limit depends on the instance type. Important As a cluster administrator, you must use either in-tree or Container Storage Interface (CSI) volumes and their respective storage classes, but never both volume types at the same time. The maximum attached EBS volume number is counted separately for in-tree and CSI volumes, which means you could have up to 39 EBS volumes of each type. For information about accessing additional storage options, such as volume snapshots, that are not possible with in-tree volume plug-ins, see AWS Elastic Block Store CSI Driver Operator . 4.1.5. Encrypting container persistent volumes on AWS with a KMS key Defining a KMS key to encrypt container-persistent volumes on AWS is useful when you have explicit compliance and security guidelines when deploying to AWS. Prerequisites Underlying infrastructure must contain storage. You must create a customer KMS key on AWS. Procedure Create a storage class: USD cat << EOF | oc create -f - apiVersion: storage.k8s.io/v1 kind: StorageClass metadata: name: <storage-class-name> 1 parameters: fsType: ext4 2 encrypted: "true" kmsKeyId: keyvalue 3 provisioner: ebs.csi.aws.com reclaimPolicy: Delete volumeBindingMode: WaitForFirstConsumer EOF 1 Specifies the name of the storage class. 2 File system that is created on provisioned volumes. 3 Specifies the full Amazon Resource Name (ARN) of the key to use when encrypting the container-persistent volume. If you do not provide any key, but the encrypted field is set to true , then the default KMS key is used. See Finding the key ID and key ARN on AWS in the AWS documentation. Create a persistent volume claim (PVC) with the storage class specifying the KMS key: USD cat << EOF | oc create -f - apiVersion: v1 kind: PersistentVolumeClaim metadata: name: mypvc spec: accessModes: - ReadWriteOnce volumeMode: Filesystem storageClassName: <storage-class-name> resources: requests: storage: 1Gi EOF Create workload containers to consume the PVC: USD cat << EOF | oc create -f - kind: Pod metadata: name: mypod spec: containers: - name: httpd image: quay.io/centos7/httpd-24-centos7 ports: - containerPort: 80 volumeMounts: - mountPath: /mnt/storage name: data volumes: - name: data persistentVolumeClaim: claimName: mypvc EOF 4.1.6. Additional resources See AWS Elastic Block Store CSI Driver Operator for information about accessing additional storage options, such as volume snapshots, that are not possible with in-tree volume plugins. 4.2. Persistent storage using Azure OpenShift Container Platform supports Microsoft Azure Disk volumes. You can provision your OpenShift Container Platform cluster with persistent storage using Azure. Some familiarity with Kubernetes and Azure is assumed. The Kubernetes persistent volume framework allows administrators to provision a cluster with persistent storage and gives users a way to request those resources without having any knowledge of the underlying infrastructure. Azure Disk volumes can be provisioned dynamically. Persistent volumes are not bound to a single project or namespace; they can be shared across the OpenShift Container Platform cluster. Persistent volume claims are specific to a project or namespace and can be requested by users. Important OpenShift Container Platform 4.11 and later provides automatic migration for the Azure Disk in-tree volume plugin to its equivalent CSI driver. CSI automatic migration should be seamless. Migration does not change how you use all existing API objects, such as persistent volumes, persistent volume claims, and storage classes. For more information about migration, see CSI automatic migration . Important High availability of storage in the infrastructure is left to the underlying storage provider. Additional resources Microsoft Azure Disk 4.2.1. Creating the Azure storage class Storage classes are used to differentiate and delineate storage levels and usages. By defining a storage class, users can obtain dynamically provisioned persistent volumes. Procedure In the OpenShift Container Platform console, click Storage Storage Classes . In the storage class overview, click Create Storage Class . Define the desired options on the page that appears. Enter a name to reference the storage class. Enter an optional description. Select the reclaim policy. Select kubernetes.io/azure-disk from the drop down list. Enter the storage account type. This corresponds to your Azure storage account SKU tier. Valid options are Premium_LRS , PremiumV2_LRS , Standard_LRS , StandardSSD_LRS , and UltraSSD_LRS . Important The skuname PremiumV2_LRS is not supported in all regions, and in some supported regions, not all of the availability zones are supported. For more information, see Azure doc . Enter the kind of account. Valid options are shared , dedicated, and managed . Important Red Hat only supports the use of kind: Managed in the storage class. With Shared and Dedicated , Azure creates unmanaged disks, while OpenShift Container Platform creates a managed disk for machine OS (root) disks. But because Azure Disk does not allow the use of both managed and unmanaged disks on a node, unmanaged disks created with Shared or Dedicated cannot be attached to OpenShift Container Platform nodes. Enter additional parameters for the storage class as desired. Click Create to create the storage class. Additional resources Azure Disk Storage Class 4.2.2. Creating the persistent volume claim Prerequisites Storage must exist in the underlying infrastructure before it can be mounted as a volume in OpenShift Container Platform. Procedure In the OpenShift Container Platform console, click Storage Persistent Volume Claims . In the persistent volume claims overview, click Create Persistent Volume Claim . Define the desired options on the page that appears. Select the previously-created storage class from the drop-down menu. Enter a unique name for the storage claim. Select the access mode. This selection determines the read and write access for the storage claim. Define the size of the storage claim. Click Create to create the persistent volume claim and generate a persistent volume. 4.2.3. Volume format Before OpenShift Container Platform mounts the volume and passes it to a container, it checks that it contains a file system as specified by the fsType parameter in the persistent volume definition. If the device is not formatted with the file system, all data from the device is erased and the device is automatically formatted with the given file system. This allows using unformatted Azure volumes as persistent volumes, because OpenShift Container Platform formats them before the first use. 4.2.4. Machine sets that deploy machines with ultra disks using PVCs You can create a machine set running on Azure that deploys machines with ultra disks. Ultra disks are high-performance storage that are intended for use with the most demanding data workloads. Both the in-tree plugin and CSI driver support using PVCs to enable ultra disks. You can also deploy machines with ultra disks as data disks without creating a PVC. Additional resources Microsoft Azure ultra disks documentation Machine sets that deploy machines on ultra disks using CSI PVCs Machine sets that deploy machines on ultra disks as data disks 4.2.4.1. Creating machines with ultra disks by using machine sets You can deploy machines with ultra disks on Azure by editing your machine set YAML file. Prerequisites Have an existing Microsoft Azure cluster. Procedure Copy an existing Azure MachineSet custom resource (CR) and edit it by running the following command: USD oc edit machineset <machine-set-name> where <machine-set-name> is the machine set that you want to provision machines with ultra disks. Add the following lines in the positions indicated: apiVersion: machine.openshift.io/v1beta1 kind: MachineSet spec: template: spec: metadata: labels: disk: ultrassd 1 providerSpec: value: ultraSSDCapability: Enabled 2 1 Specify a label to use to select a node that is created by this machine set. This procedure uses disk.ultrassd for this value. 2 These lines enable the use of ultra disks. Create a machine set using the updated configuration by running the following command: USD oc create -f <machine-set-name>.yaml Create a storage class that contains the following YAML definition: apiVersion: storage.k8s.io/v1 kind: StorageClass metadata: name: ultra-disk-sc 1 parameters: cachingMode: None diskIopsReadWrite: "2000" 2 diskMbpsReadWrite: "320" 3 kind: managed skuname: UltraSSD_LRS provisioner: disk.csi.azure.com 4 reclaimPolicy: Delete volumeBindingMode: WaitForFirstConsumer 5 1 Specify the name of the storage class. This procedure uses ultra-disk-sc for this value. 2 Specify the number of IOPS for the storage class. 3 Specify the throughput in MBps for the storage class. 4 For Azure Kubernetes Service (AKS) version 1.21 or later, use disk.csi.azure.com . For earlier versions of AKS, use kubernetes.io/azure-disk . 5 Optional: Specify this parameter to wait for the creation of the pod that will use the disk. Create a persistent volume claim (PVC) to reference the ultra-disk-sc storage class that contains the following YAML definition: apiVersion: v1 kind: PersistentVolumeClaim metadata: name: ultra-disk 1 spec: accessModes: - ReadWriteOnce storageClassName: ultra-disk-sc 2 resources: requests: storage: 4Gi 3 1 Specify the name of the PVC. This procedure uses ultra-disk for this value. 2 This PVC references the ultra-disk-sc storage class. 3 Specify the size for the storage class. The minimum value is 4Gi . Create a pod that contains the following YAML definition: apiVersion: v1 kind: Pod metadata: name: nginx-ultra spec: nodeSelector: disk: ultrassd 1 containers: - name: nginx-ultra image: alpine:latest command: - "sleep" - "infinity" volumeMounts: - mountPath: "/mnt/azure" name: volume volumes: - name: volume persistentVolumeClaim: claimName: ultra-disk 2 1 Specify the label of the machine set that enables the use of ultra disks. This procedure uses disk.ultrassd for this value. 2 This pod references the ultra-disk PVC. Verification Validate that the machines are created by running the following command: USD oc get machines The machines should be in the Running state. For a machine that is running and has a node attached, validate the partition by running the following command: USD oc debug node/<node-name> -- chroot /host lsblk In this command, oc debug node/<node-name> starts a debugging shell on the node <node-name> and passes a command with -- . The passed command chroot /host provides access to the underlying host OS binaries, and lsblk shows the block devices that are attached to the host OS machine. steps To use an ultra disk from within a pod, create a workload that uses the mount point. Create a YAML file similar to the following example: apiVersion: v1 kind: Pod metadata: name: ssd-benchmark1 spec: containers: - name: ssd-benchmark1 image: nginx ports: - containerPort: 80 name: "http-server" volumeMounts: - name: lun0p1 mountPath: "/tmp" volumes: - name: lun0p1 hostPath: path: /var/lib/lun0p1 type: DirectoryOrCreate nodeSelector: disktype: ultrassd 4.2.4.2. Troubleshooting resources for machine sets that enable ultra disks Use the information in this section to understand and recover from issues you might encounter. 4.2.4.2.1. Unable to mount a persistent volume claim backed by an ultra disk If there is an issue mounting a persistent volume claim backed by an ultra disk, the pod becomes stuck in the ContainerCreating state and an alert is triggered. For example, if the additionalCapabilities.ultraSSDEnabled parameter is not set on the machine that backs the node that hosts the pod, the following error message appears: StorageAccountType UltraSSD_LRS can be used only when additionalCapabilities.ultraSSDEnabled is set. To resolve this issue, describe the pod by running the following command: USD oc -n <stuck_pod_namespace> describe pod <stuck_pod_name> 4.3. Persistent storage using Azure File OpenShift Container Platform supports Microsoft Azure File volumes. You can provision your OpenShift Container Platform cluster with persistent storage using Azure. Some familiarity with Kubernetes and Azure is assumed. The Kubernetes persistent volume framework allows administrators to provision a cluster with persistent storage and gives users a way to request those resources without having any knowledge of the underlying infrastructure. You can provision Azure File volumes dynamically. Persistent volumes are not bound to a single project or namespace, and you can share them across the OpenShift Container Platform cluster. Persistent volume claims are specific to a project or namespace, and can be requested by users for use in applications. Important High availability of storage in the infrastructure is left to the underlying storage provider. Important Azure File volumes use Server Message Block. Important OpenShift Container Platform 4.13 and later provides automatic migration for the Azure File in-tree volume plugin to its equivalent CSI driver. CSI automatic migration should be seamless. Migration does not change how you use all existing API objects, such as persistent volumes, persistent volume claims, and storage classes. For more information about migration, see CSI automatic migration . Additional resources Azure Files 4.3.1. Create the Azure File share persistent volume claim To create the persistent volume claim, you must first define a Secret object that contains the Azure account and key. This secret is used in the PersistentVolume definition, and will be referenced by the persistent volume claim for use in applications. Prerequisites An Azure File share exists. The credentials to access this share, specifically the storage account and key, are available. Procedure Create a Secret object that contains the Azure File credentials: USD oc create secret generic <secret-name> --from-literal=azurestorageaccountname=<storage-account> \ 1 --from-literal=azurestorageaccountkey=<storage-account-key> 2 1 The Azure File storage account name. 2 The Azure File storage account key. Create a PersistentVolume object that references the Secret object you created: apiVersion: "v1" kind: "PersistentVolume" metadata: name: "pv0001" 1 spec: capacity: storage: "5Gi" 2 accessModes: - "ReadWriteOnce" storageClassName: azure-file-sc azureFile: secretName: <secret-name> 3 shareName: share-1 4 readOnly: false 1 The name of the persistent volume. 2 The size of this persistent volume. 3 The name of the secret that contains the Azure File share credentials. 4 The name of the Azure File share. Create a PersistentVolumeClaim object that maps to the persistent volume you created: apiVersion: "v1" kind: "PersistentVolumeClaim" metadata: name: "claim1" 1 spec: accessModes: - "ReadWriteOnce" resources: requests: storage: "5Gi" 2 storageClassName: azure-file-sc 3 volumeName: "pv0001" 4 1 The name of the persistent volume claim. 2 The size of this persistent volume claim. 3 The name of the storage class that is used to provision the persistent volume. Specify the storage class used in the PersistentVolume definition. 4 The name of the existing PersistentVolume object that references the Azure File share. 4.3.2. Mount the Azure File share in a pod After the persistent volume claim has been created, it can be used inside by an application. The following example demonstrates mounting this share inside of a pod. Prerequisites A persistent volume claim exists that is mapped to the underlying Azure File share. Procedure Create a pod that mounts the existing persistent volume claim: apiVersion: v1 kind: Pod metadata: name: pod-name 1 spec: containers: ... volumeMounts: - mountPath: "/data" 2 name: azure-file-share volumes: - name: azure-file-share persistentVolumeClaim: claimName: claim1 3 1 The name of the pod. 2 The path to mount the Azure File share inside the pod. Do not mount to the container root, / , or any path that is the same in the host and the container. This can corrupt your host system if the container is sufficiently privileged, such as the host /dev/pts files. It is safe to mount the host by using /host . 3 The name of the PersistentVolumeClaim object that has been previously created. 4.4. Persistent storage using Cinder OpenShift Container Platform supports OpenStack Cinder. Some familiarity with Kubernetes and OpenStack is assumed. Cinder volumes can be provisioned dynamically. Persistent volumes are not bound to a single project or namespace; they can be shared across the OpenShift Container Platform cluster. Persistent volume claims are specific to a project or namespace and can be requested by users. Important OpenShift Container Platform 4.11 and later provides automatic migration for the Cinder in-tree volume plugin to its equivalent CSI driver. CSI automatic migration should be seamless. Migration does not change how you use all existing API objects, such as persistent volumes, persistent volume claims, and storage classes. For more information about migration, see CSI automatic migration . Additional resources For more information about how OpenStack Block Storage provides persistent block storage management for virtual hard drives, see OpenStack Cinder . 4.4.1. Manual provisioning with Cinder Storage must exist in the underlying infrastructure before it can be mounted as a volume in OpenShift Container Platform. Prerequisites OpenShift Container Platform configured for Red Hat OpenStack Platform (RHOSP) Cinder volume ID 4.4.1.1. Creating the persistent volume You must define your persistent volume (PV) in an object definition before creating it in OpenShift Container Platform: Procedure Save your object definition to a file. cinder-persistentvolume.yaml apiVersion: "v1" kind: "PersistentVolume" metadata: name: "pv0001" 1 spec: capacity: storage: "5Gi" 2 accessModes: - "ReadWriteOnce" cinder: 3 fsType: "ext3" 4 volumeID: "f37a03aa-6212-4c62-a805-9ce139fab180" 5 1 The name of the volume that is used by persistent volume claims or pods. 2 The amount of storage allocated to this volume. 3 Indicates cinder for Red Hat OpenStack Platform (RHOSP) Cinder volumes. 4 The file system that is created when the volume is mounted for the first time. 5 The Cinder volume to use. Important Do not change the fstype parameter value after the volume is formatted and provisioned. Changing this value can result in data loss and pod failure. Create the object definition file you saved in the step. USD oc create -f cinder-persistentvolume.yaml 4.4.1.2. Persistent volume formatting You can use unformatted Cinder volumes as PVs because OpenShift Container Platform formats them before the first use. Before OpenShift Container Platform mounts the volume and passes it to a container, the system checks that it contains a file system as specified by the fsType parameter in the PV definition. If the device is not formatted with the file system, all data from the device is erased and the device is automatically formatted with the given file system. 4.4.1.3. Cinder volume security If you use Cinder PVs in your application, configure security for their deployment configurations. Prerequisites An SCC must be created that uses the appropriate fsGroup strategy. Procedure Create a service account and add it to the SCC: USD oc create serviceaccount <service_account> USD oc adm policy add-scc-to-user <new_scc> -z <service_account> -n <project> In your application's deployment configuration, provide the service account name and securityContext : apiVersion: v1 kind: ReplicationController metadata: name: frontend-1 spec: replicas: 1 1 selector: 2 name: frontend template: 3 metadata: labels: 4 name: frontend 5 spec: containers: - image: openshift/hello-openshift name: helloworld ports: - containerPort: 8080 protocol: TCP restartPolicy: Always serviceAccountName: <service_account> 6 securityContext: fsGroup: 7777 7 1 The number of copies of the pod to run. 2 The label selector of the pod to run. 3 A template for the pod that the controller creates. 4 The labels on the pod. They must include labels from the label selector. 5 The maximum name length after expanding any parameters is 63 characters. 6 Specifies the service account you created. 7 Specifies an fsGroup for the pods. 4.5. Persistent storage using Fibre Channel OpenShift Container Platform supports Fibre Channel, allowing you to provision your OpenShift Container Platform cluster with persistent storage using Fibre channel volumes. Some familiarity with Kubernetes and Fibre Channel is assumed. Important Persistent storage using Fibre Channel is not supported on ARM architecture based infrastructures. The Kubernetes persistent volume framework allows administrators to provision a cluster with persistent storage and gives users a way to request those resources without having any knowledge of the underlying infrastructure. Persistent volumes are not bound to a single project or namespace; they can be shared across the OpenShift Container Platform cluster. Persistent volume claims are specific to a project or namespace and can be requested by users. Important High availability of storage in the infrastructure is left to the underlying storage provider. Additional resources Using Fibre Channel devices 4.5.1. Provisioning To provision Fibre Channel volumes using the PersistentVolume API the following must be available: The targetWWNs (array of Fibre Channel target's World Wide Names). A valid LUN number. The filesystem type. A persistent volume and a LUN have a one-to-one mapping between them. Prerequisites Fibre Channel LUNs must exist in the underlying infrastructure. PersistentVolume object definition apiVersion: v1 kind: PersistentVolume metadata: name: pv0001 spec: capacity: storage: 1Gi accessModes: - ReadWriteOnce fc: wwids: [scsi-3600508b400105e210000900000490000] 1 targetWWNs: ['500a0981891b8dc5', '500a0981991b8dc5'] 2 lun: 2 3 fsType: ext4 1 World wide identifiers (WWIDs). Either FC wwids or a combination of FC targetWWNs and lun must be set, but not both simultaneously. The FC WWID identifier is recommended over the WWNs target because it is guaranteed to be unique for every storage device, and independent of the path that is used to access the device. The WWID identifier can be obtained by issuing a SCSI Inquiry to retrieve the Device Identification Vital Product Data ( page 0x83 ) or Unit Serial Number ( page 0x80 ). FC WWIDs are identified as /dev/disk/by-id/ to reference the data on the disk, even if the path to the device changes and even when accessing the device from different systems. 2 3 Fibre Channel WWNs are identified as /dev/disk/by-path/pci-<IDENTIFIER>-fc-0x<WWN>-lun-<LUN#> , but you do not need to provide any part of the path leading up to the WWN , including the 0x , and anything after, including the - (hyphen). Important Changing the value of the fstype parameter after the volume has been formatted and provisioned can result in data loss and pod failure. 4.5.1.1. Enforcing disk quotas Use LUN partitions to enforce disk quotas and size constraints. Each LUN is mapped to a single persistent volume, and unique names must be used for persistent volumes. Enforcing quotas in this way allows the end user to request persistent storage by a specific amount, such as 10Gi, and be matched with a corresponding volume of equal or greater capacity. 4.5.1.2. Fibre Channel volume security Users request storage with a persistent volume claim. This claim only lives in the user's namespace, and can only be referenced by a pod within that same namespace. Any attempt to access a persistent volume across a namespace causes the pod to fail. Each Fibre Channel LUN must be accessible by all nodes in the cluster. 4.6. Persistent storage using FlexVolume Important FlexVolume is a deprecated feature. Deprecated functionality is still included in OpenShift Container Platform and continues to be supported; however, it will be removed in a future release of this product and is not recommended for new deployments. Out-of-tree Container Storage Interface (CSI) driver is the recommended way to write volume drivers in OpenShift Container Platform. Maintainers of FlexVolume drivers should implement a CSI driver and move users of FlexVolume to CSI. Users of FlexVolume should move their workloads to CSI driver. For the most recent list of major functionality that has been deprecated or removed within OpenShift Container Platform, refer to the Deprecated and removed features section of the OpenShift Container Platform release notes. OpenShift Container Platform supports FlexVolume, an out-of-tree plugin that uses an executable model to interface with drivers. To use storage from a back-end that does not have a built-in plugin, you can extend OpenShift Container Platform through FlexVolume drivers and provide persistent storage to applications. Pods interact with FlexVolume drivers through the flexvolume in-tree plugin. Additional resources Expanding persistent volumes 4.6.1. About FlexVolume drivers A FlexVolume driver is an executable file that resides in a well-defined directory on all nodes in the cluster. OpenShift Container Platform calls the FlexVolume driver whenever it needs to mount or unmount a volume represented by a PersistentVolume object with flexVolume as the source. Important Attach and detach operations are not supported in OpenShift Container Platform for FlexVolume. 4.6.2. FlexVolume driver example The first command-line argument of the FlexVolume driver is always an operation name. Other parameters are specific to each operation. Most of the operations take a JavaScript Object Notation (JSON) string as a parameter. This parameter is a complete JSON string, and not the name of a file with the JSON data. The FlexVolume driver contains: All flexVolume.options . Some options from flexVolume prefixed by kubernetes.io/ , such as fsType and readwrite . The content of the referenced secret, if specified, prefixed by kubernetes.io/secret/ . FlexVolume driver JSON input example { "fooServer": "192.168.0.1:1234", 1 "fooVolumeName": "bar", "kubernetes.io/fsType": "ext4", 2 "kubernetes.io/readwrite": "ro", 3 "kubernetes.io/secret/<key name>": "<key value>", 4 "kubernetes.io/secret/<another key name>": "<another key value>", } 1 All options from flexVolume.options . 2 The value of flexVolume.fsType . 3 ro / rw based on flexVolume.readOnly . 4 All keys and their values from the secret referenced by flexVolume.secretRef . OpenShift Container Platform expects JSON data on standard output of the driver. When not specified, the output describes the result of the operation. FlexVolume driver default output example { "status": "<Success/Failure/Not supported>", "message": "<Reason for success/failure>" } Exit code of the driver should be 0 for success and 1 for error. Operations should be idempotent, which means that the mounting of an already mounted volume should result in a successful operation. 4.6.3. Installing FlexVolume drivers FlexVolume drivers that are used to extend OpenShift Container Platform are executed only on the node. To implement FlexVolumes, a list of operations to call and the installation path are all that is required. Prerequisites FlexVolume drivers must implement these operations: init Initializes the driver. It is called during initialization of all nodes. Arguments: none Executed on: node Expected output: default JSON mount Mounts a volume to directory. This can include anything that is necessary to mount the volume, including finding the device and then mounting the device. Arguments: <mount-dir> <json> Executed on: node Expected output: default JSON unmount Unmounts a volume from a directory. This can include anything that is necessary to clean up the volume after unmounting. Arguments: <mount-dir> Executed on: node Expected output: default JSON mountdevice Mounts a volume's device to a directory where individual pods can then bind mount. This call-out does not pass "secrets" specified in the FlexVolume spec. If your driver requires secrets, do not implement this call-out. Arguments: <mount-dir> <json> Executed on: node Expected output: default JSON unmountdevice Unmounts a volume's device from a directory. Arguments: <mount-dir> Executed on: node Expected output: default JSON All other operations should return JSON with {"status": "Not supported"} and exit code 1 . Procedure To install the FlexVolume driver: Ensure that the executable file exists on all nodes in the cluster. Place the executable file at the volume plugin path: /etc/kubernetes/kubelet-plugins/volume/exec/<vendor>~<driver>/<driver> . For example, to install the FlexVolume driver for the storage foo , place the executable file at: /etc/kubernetes/kubelet-plugins/volume/exec/openshift.com~foo/foo . 4.6.4. Consuming storage using FlexVolume drivers Each PersistentVolume object in OpenShift Container Platform represents one storage asset in the storage back-end, such as a volume. Procedure Use the PersistentVolume object to reference the installed storage. Persistent volume object definition using FlexVolume drivers example apiVersion: v1 kind: PersistentVolume metadata: name: pv0001 1 spec: capacity: storage: 1Gi 2 accessModes: - ReadWriteOnce flexVolume: driver: openshift.com/foo 3 fsType: "ext4" 4 secretRef: foo-secret 5 readOnly: true 6 options: 7 fooServer: 192.168.0.1:1234 fooVolumeName: bar 1 The name of the volume. This is how it is identified through persistent volume claims or from pods. This name can be different from the name of the volume on back-end storage. 2 The amount of storage allocated to this volume. 3 The name of the driver. This field is mandatory. 4 The file system that is present on the volume. This field is optional. 5 The reference to a secret. Keys and values from this secret are provided to the FlexVolume driver on invocation. This field is optional. 6 The read-only flag. This field is optional. 7 The additional options for the FlexVolume driver. In addition to the flags specified by the user in the options field, the following flags are also passed to the executable: Note Secrets are passed only to mount or unmount call-outs. 4.7. Persistent storage using GCE Persistent Disk OpenShift Container Platform supports GCE Persistent Disk volumes (gcePD). You can provision your OpenShift Container Platform cluster with persistent storage using GCE. Some familiarity with Kubernetes and GCE is assumed. The Kubernetes persistent volume framework allows administrators to provision a cluster with persistent storage and gives users a way to request those resources without having any knowledge of the underlying infrastructure. GCE Persistent Disk volumes can be provisioned dynamically. Persistent volumes are not bound to a single project or namespace; they can be shared across the OpenShift Container Platform cluster. Persistent volume claims are specific to a project or namespace and can be requested by users. Important OpenShift Container Platform 4.12 and later provides automatic migration for the GCE Persist Disk in-tree volume plugin to its equivalent CSI driver. CSI automatic migration should be seamless. Migration does not change how you use all existing API objects, such as persistent volumes, persistent volume claims, and storage classes. For more information about migration, see CSI automatic migration . Important High availability of storage in the infrastructure is left to the underlying storage provider. Additional resources GCE Persistent Disk 4.7.1. Creating the GCE storage class Storage classes are used to differentiate and delineate storage levels and usages. By defining a storage class, users can obtain dynamically provisioned persistent volumes. 4.7.2. Creating the persistent volume claim Prerequisites Storage must exist in the underlying infrastructure before it can be mounted as a volume in OpenShift Container Platform. Procedure In the OpenShift Container Platform console, click Storage Persistent Volume Claims . In the persistent volume claims overview, click Create Persistent Volume Claim . Define the desired options on the page that appears. Select the previously-created storage class from the drop-down menu. Enter a unique name for the storage claim. Select the access mode. This selection determines the read and write access for the storage claim. Define the size of the storage claim. Click Create to create the persistent volume claim and generate a persistent volume. 4.7.3. Volume format Before OpenShift Container Platform mounts the volume and passes it to a container, it checks that the volume contains a file system as specified by the fsType parameter in the persistent volume definition. If the device is not formatted with the file system, all data from the device is erased and the device is automatically formatted with the given file system. This verification enables you to use unformatted GCE volumes as persistent volumes, because OpenShift Container Platform formats them before the first use. 4.8. Persistent storage using iSCSI You can provision your OpenShift Container Platform cluster with persistent storage using iSCSI . Some familiarity with Kubernetes and iSCSI is assumed. The Kubernetes persistent volume framework allows administrators to provision a cluster with persistent storage and gives users a way to request those resources without having any knowledge of the underlying infrastructure. Important High-availability of storage in the infrastructure is left to the underlying storage provider. Important When you use iSCSI on Amazon Web Services, you must update the default security policy to include TCP traffic between nodes on the iSCSI ports. By default, they are ports 860 and 3260 . Important Users must ensure that the iSCSI initiator is already configured on all OpenShift Container Platform nodes by installing the iscsi-initiator-utils package and configuring their initiator name in /etc/iscsi/initiatorname.iscsi . The iscsi-initiator-utils package is already installed on deployments that use Red Hat Enterprise Linux CoreOS (RHCOS). For more information, see Managing Storage Devices . 4.8.1. Provisioning Verify that the storage exists in the underlying infrastructure before mounting it as a volume in OpenShift Container Platform. All that is required for the iSCSI is the iSCSI target portal, a valid iSCSI Qualified Name (IQN), a valid LUN number, the filesystem type, and the PersistentVolume API. PersistentVolume object definition apiVersion: v1 kind: PersistentVolume metadata: name: iscsi-pv spec: capacity: storage: 1Gi accessModes: - ReadWriteOnce iscsi: targetPortal: 10.16.154.81:3260 iqn: iqn.2014-12.example.server:storage.target00 lun: 0 fsType: 'ext4' 4.8.2. Enforcing disk quotas Use LUN partitions to enforce disk quotas and size constraints. Each LUN is one persistent volume. Kubernetes enforces unique names for persistent volumes. Enforcing quotas in this way allows the end user to request persistent storage by a specific amount (for example, 10Gi ) and be matched with a corresponding volume of equal or greater capacity. 4.8.3. iSCSI volume security Users request storage with a PersistentVolumeClaim object. This claim only lives in the user's namespace and can only be referenced by a pod within that same namespace. Any attempt to access a persistent volume claim across a namespace causes the pod to fail. Each iSCSI LUN must be accessible by all nodes in the cluster. 4.8.3.1. Challenge Handshake Authentication Protocol (CHAP) configuration Optionally, OpenShift Container Platform can use CHAP to authenticate itself to iSCSI targets: apiVersion: v1 kind: PersistentVolume metadata: name: iscsi-pv spec: capacity: storage: 1Gi accessModes: - ReadWriteOnce iscsi: targetPortal: 10.0.0.1:3260 iqn: iqn.2016-04.test.com:storage.target00 lun: 0 fsType: ext4 chapAuthDiscovery: true 1 chapAuthSession: true 2 secretRef: name: chap-secret 3 1 Enable CHAP authentication of iSCSI discovery. 2 Enable CHAP authentication of iSCSI session. 3 Specify name of Secrets object with user name + password. This Secret object must be available in all namespaces that can use the referenced volume. 4.8.4. iSCSI multipathing For iSCSI-based storage, you can configure multiple paths by using the same IQN for more than one target portal IP address. Multipathing ensures access to the persistent volume when one or more of the components in a path fail. To specify multi-paths in the pod specification, use the portals field. For example: apiVersion: v1 kind: PersistentVolume metadata: name: iscsi-pv spec: capacity: storage: 1Gi accessModes: - ReadWriteOnce iscsi: targetPortal: 10.0.0.1:3260 portals: ['10.0.2.16:3260', '10.0.2.17:3260', '10.0.2.18:3260'] 1 iqn: iqn.2016-04.test.com:storage.target00 lun: 0 fsType: ext4 readOnly: false 1 Add additional target portals using the portals field. 4.8.5. iSCSI custom initiator IQN Configure the custom initiator iSCSI Qualified Name (IQN) if the iSCSI targets are restricted to certain IQNs, but the nodes that the iSCSI PVs are attached to are not guaranteed to have these IQNs. To specify a custom initiator IQN, use initiatorName field. apiVersion: v1 kind: PersistentVolume metadata: name: iscsi-pv spec: capacity: storage: 1Gi accessModes: - ReadWriteOnce iscsi: targetPortal: 10.0.0.1:3260 portals: ['10.0.2.16:3260', '10.0.2.17:3260', '10.0.2.18:3260'] iqn: iqn.2016-04.test.com:storage.target00 lun: 0 initiatorName: iqn.2016-04.test.com:custom.iqn 1 fsType: ext4 readOnly: false 1 Specify the name of the initiator. 4.9. Persistent storage using NFS OpenShift Container Platform clusters can be provisioned with persistent storage using NFS. Persistent volumes (PVs) and persistent volume claims (PVCs) provide a convenient method for sharing a volume across a project. While the NFS-specific information contained in a PV definition could also be defined directly in a Pod definition, doing so does not create the volume as a distinct cluster resource, making the volume more susceptible to conflicts. Additional resources Mounting NFS shares 4.9.1. Provisioning Storage must exist in the underlying infrastructure before it can be mounted as a volume in OpenShift Container Platform. To provision NFS volumes, a list of NFS servers and export paths are all that is required. Procedure Create an object definition for the PV: apiVersion: v1 kind: PersistentVolume metadata: name: pv0001 1 spec: capacity: storage: 5Gi 2 accessModes: - ReadWriteOnce 3 nfs: 4 path: /tmp 5 server: 172.17.0.2 6 persistentVolumeReclaimPolicy: Retain 7 1 The name of the volume. This is the PV identity in various oc <command> pod commands. 2 The amount of storage allocated to this volume. 3 Though this appears to be related to controlling access to the volume, it is actually used similarly to labels and used to match a PVC to a PV. Currently, no access rules are enforced based on the accessModes . 4 The volume type being used, in this case the nfs plugin. 5 The path that is exported by the NFS server. 6 The hostname or IP address of the NFS server. 7 The reclaim policy for the PV. This defines what happens to a volume when released. Note Each NFS volume must be mountable by all schedulable nodes in the cluster. Verify that the PV was created: USD oc get pv Example output NAME LABELS CAPACITY ACCESSMODES STATUS CLAIM REASON AGE pv0001 <none> 5Gi RWO Available 31s Create a persistent volume claim that binds to the new PV: apiVersion: v1 kind: PersistentVolumeClaim metadata: name: nfs-claim1 spec: accessModes: - ReadWriteOnce 1 resources: requests: storage: 5Gi 2 volumeName: pv0001 storageClassName: "" 1 The access modes do not enforce security, but rather act as labels to match a PV to a PVC. 2 This claim looks for PVs offering 5Gi or greater capacity. Verify that the persistent volume claim was created: USD oc get pvc Example output NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE nfs-claim1 Bound pv0001 5Gi RWO 2m 4.9.2. Enforcing disk quotas You can use disk partitions to enforce disk quotas and size constraints. Each partition can be its own export. Each export is one PV. OpenShift Container Platform enforces unique names for PVs, but the uniqueness of the NFS volume's server and path is up to the administrator. Enforcing quotas in this way allows the developer to request persistent storage by a specific amount, such as 10Gi, and be matched with a corresponding volume of equal or greater capacity. 4.9.3. NFS volume security This section covers NFS volume security, including matching permissions and SELinux considerations. The user is expected to understand the basics of POSIX permissions, process UIDs, supplemental groups, and SELinux. Developers request NFS storage by referencing either a PVC by name or the NFS volume plugin directly in the volumes section of their Pod definition. The /etc/exports file on the NFS server contains the accessible NFS directories. The target NFS directory has POSIX owner and group IDs. The OpenShift Container Platform NFS plugin mounts the container's NFS directory with the same POSIX ownership and permissions found on the exported NFS directory. However, the container is not run with its effective UID equal to the owner of the NFS mount, which is the desired behavior. As an example, if the target NFS directory appears on the NFS server as: USD ls -lZ /opt/nfs -d Example output drwxrws---. nfsnobody 5555 unconfined_u:object_r:usr_t:s0 /opt/nfs USD id nfsnobody Example output uid=65534(nfsnobody) gid=65534(nfsnobody) groups=65534(nfsnobody) Then the container must match SELinux labels, and either run with a UID of 65534 , the nfsnobody owner, or with 5555 in its supplemental groups to access the directory. Note The owner ID of 65534 is used as an example. Even though NFS's root_squash maps root , uid 0 , to nfsnobody , uid 65534 , NFS exports can have arbitrary owner IDs. Owner 65534 is not required for NFS exports. 4.9.3.1. Group IDs The recommended way to handle NFS access, assuming it is not an option to change permissions on the NFS export, is to use supplemental groups. Supplemental groups in OpenShift Container Platform are used for shared storage, of which NFS is an example. In contrast, block storage such as iSCSI uses the fsGroup SCC strategy and the fsGroup value in the securityContext of the pod. Note To gain access to persistent storage, it is generally preferable to use supplemental group IDs versus user IDs. Because the group ID on the example target NFS directory is 5555 , the pod can define that group ID using supplementalGroups under the securityContext definition of the pod. For example: spec: containers: - name: ... securityContext: 1 supplementalGroups: [5555] 2 1 securityContext must be defined at the pod level, not under a specific container. 2 An array of GIDs defined for the pod. In this case, there is one element in the array. Additional GIDs would be comma-separated. Assuming there are no custom SCCs that might satisfy the pod requirements, the pod likely matches the restricted SCC. This SCC has the supplementalGroups strategy set to RunAsAny , meaning that any supplied group ID is accepted without range checking. As a result, the above pod passes admissions and is launched. However, if group ID range checking is desired, a custom SCC is the preferred solution. A custom SCC can be created such that minimum and maximum group IDs are defined, group ID range checking is enforced, and a group ID of 5555 is allowed. Note To use a custom SCC, you must first add it to the appropriate service account. For example, use the default service account in the given project unless another has been specified on the Pod specification. 4.9.3.2. User IDs User IDs can be defined in the container image or in the Pod definition. Note It is generally preferable to use supplemental group IDs to gain access to persistent storage versus using user IDs. In the example target NFS directory shown above, the container needs its UID set to 65534 , ignoring group IDs for the moment, so the following can be added to the Pod definition: spec: containers: 1 - name: ... securityContext: runAsUser: 65534 2 1 Pods contain a securityContext definition specific to each container and a pod's securityContext which applies to all containers defined in the pod. 2 65534 is the nfsnobody user. Assuming that the project is default and the SCC is restricted , the user ID of 65534 as requested by the pod is not allowed. Therefore, the pod fails for the following reasons: It requests 65534 as its user ID. All SCCs available to the pod are examined to see which SCC allows a user ID of 65534 . While all policies of the SCCs are checked, the focus here is on user ID. Because all available SCCs use MustRunAsRange for their runAsUser strategy, UID range checking is required. 65534 is not included in the SCC or project's user ID range. It is generally considered a good practice not to modify the predefined SCCs. The preferred way to fix this situation is to create a custom SCC A custom SCC can be created such that minimum and maximum user IDs are defined, UID range checking is still enforced, and the UID of 65534 is allowed. Note To use a custom SCC, you must first add it to the appropriate service account. For example, use the default service account in the given project unless another has been specified on the Pod specification. 4.9.3.3. SELinux Red Hat Enterprise Linux (RHEL) and Red Hat Enterprise Linux CoreOS (RHCOS) systems are configured to use SELinux on remote NFS servers by default. For non-RHEL and non-RHCOS systems, SELinux does not allow writing from a pod to a remote NFS server. The NFS volume mounts correctly but it is read-only. You will need to enable the correct SELinux permissions by using the following procedure. Prerequisites The container-selinux package must be installed. This package provides the virt_use_nfs SELinux boolean. Procedure Enable the virt_use_nfs boolean using the following command. The -P option makes this boolean persistent across reboots. # setsebool -P virt_use_nfs 1 4.9.3.4. Export settings To enable arbitrary container users to read and write the volume, each exported volume on the NFS server should conform to the following conditions: Every export must be exported using the following format: /<example_fs> *(rw,root_squash) The firewall must be configured to allow traffic to the mount point. For NFSv4, configure the default port 2049 ( nfs ). NFSv4 # iptables -I INPUT 1 -p tcp --dport 2049 -j ACCEPT For NFSv3, there are three ports to configure: 2049 ( nfs ), 20048 ( mountd ), and 111 ( portmapper ). NFSv3 # iptables -I INPUT 1 -p tcp --dport 2049 -j ACCEPT # iptables -I INPUT 1 -p tcp --dport 20048 -j ACCEPT # iptables -I INPUT 1 -p tcp --dport 111 -j ACCEPT The NFS export and directory must be set up so that they are accessible by the target pods. Either set the export to be owned by the container's primary UID, or supply the pod group access using supplementalGroups , as shown in the group IDs above. 4.9.4. Reclaiming resources NFS implements the OpenShift Container Platform Recyclable plugin interface. Automatic processes handle reclamation tasks based on policies set on each persistent volume. By default, PVs are set to Retain . Once claim to a PVC is deleted, and the PV is released, the PV object should not be reused. Instead, a new PV should be created with the same basic volume details as the original. For example, the administrator creates a PV named nfs1 : apiVersion: v1 kind: PersistentVolume metadata: name: nfs1 spec: capacity: storage: 1Mi accessModes: - ReadWriteMany nfs: server: 192.168.1.1 path: "/" The user creates PVC1 , which binds to nfs1 . The user then deletes PVC1 , releasing claim to nfs1 . This results in nfs1 being Released . If the administrator wants to make the same NFS share available, they should create a new PV with the same NFS server details, but a different PV name: apiVersion: v1 kind: PersistentVolume metadata: name: nfs2 spec: capacity: storage: 1Mi accessModes: - ReadWriteMany nfs: server: 192.168.1.1 path: "/" Deleting the original PV and re-creating it with the same name is discouraged. Attempting to manually change the status of a PV from Released to Available causes errors and potential data loss. 4.9.5. Additional configuration and troubleshooting Depending on what version of NFS is being used and how it is configured, there may be additional configuration steps needed for proper export and security mapping. The following are some that may apply: NFSv4 mount incorrectly shows all files with ownership of nobody:nobody Could be attributed to the ID mapping settings, found in /etc/idmapd.conf on your NFS. See this Red Hat Solution . Disabling ID mapping on NFSv4 On both the NFS client and server, run: # echo 'Y' > /sys/module/nfsd/parameters/nfs4_disable_idmapping 4.10. Red Hat OpenShift Data Foundation Red Hat OpenShift Data Foundation is a provider of agnostic persistent storage for OpenShift Container Platform supporting file, block, and object storage, either in-house or in hybrid clouds. As a Red Hat storage solution, Red Hat OpenShift Data Foundation is completely integrated with OpenShift Container Platform for deployment, management, and monitoring. For more information, see the Red Hat OpenShift Data Foundation documentation . Important OpenShift Data Foundation on top of Red Hat Hyperconverged Infrastructure (RHHI) for Virtualization, which uses hyperconverged nodes that host virtual machines installed with OpenShift Container Platform, is not a supported configuration. For more information about supported platforms, see the Red Hat OpenShift Data Foundation Supportability and Interoperability Guide . 4.11. Persistent storage using VMware vSphere volumes OpenShift Container Platform allows use of VMware vSphere's Virtual Machine Disk (VMDK) volumes. You can provision your OpenShift Container Platform cluster with persistent storage using VMware vSphere. Some familiarity with Kubernetes and VMware vSphere is assumed. VMware vSphere volumes can be provisioned dynamically. OpenShift Container Platform creates the disk in vSphere and attaches this disk to the correct image. Note OpenShift Container Platform provisions new volumes as independent persistent disks that can freely attach and detach the volume on any node in the cluster. Consequently, you cannot back up volumes that use snapshots, or restore volumes from snapshots. See Snapshot Limitations for more information. The Kubernetes persistent volume framework allows administrators to provision a cluster with persistent storage and gives users a way to request those resources without having any knowledge of the underlying infrastructure. Persistent volumes are not bound to a single project or namespace; they can be shared across the OpenShift Container Platform cluster. Persistent volume claims are specific to a project or namespace and can be requested by users. Important For new installations, OpenShift Container Platform 4.13 and later provides automatic migration for the vSphere in-tree volume plugin to its equivalent CSI driver. Updating to OpenShift Container Platform 4.15 and later also provides automatic migration. For more information about updating and migration, see CSI automatic migration . CSI automatic migration should be seamless. Migration does not change how you use all existing API objects, such as persistent volumes, persistent volume claims, and storage classes. Additional resources VMware vSphere 4.11.1. Dynamically provisioning VMware vSphere volumes Dynamically provisioning VMware vSphere volumes is the recommended method. 4.11.2. Prerequisites An OpenShift Container Platform cluster installed on a VMware vSphere version that meets the requirements for the components that you use. See Installing a cluster on vSphere for information about vSphere version support. You can use either of the following procedures to dynamically provision these volumes using the default storage class. 4.11.2.1. Dynamically provisioning VMware vSphere volumes using the UI OpenShift Container Platform installs a default storage class, named thin , that uses the thin disk format for provisioning volumes. Prerequisites Storage must exist in the underlying infrastructure before it can be mounted as a volume in OpenShift Container Platform. Procedure In the OpenShift Container Platform console, click Storage Persistent Volume Claims . In the persistent volume claims overview, click Create Persistent Volume Claim . Define the required options on the resulting page. Select the thin storage class. Enter a unique name for the storage claim. Select the access mode to determine the read and write access for the created storage claim. Define the size of the storage claim. Click Create to create the persistent volume claim and generate a persistent volume. 4.11.2.2. Dynamically provisioning VMware vSphere volumes using the CLI OpenShift Container Platform installs a default StorageClass, named thin , that uses the thin disk format for provisioning volumes. Prerequisites Storage must exist in the underlying infrastructure before it can be mounted as a volume in OpenShift Container Platform. Procedure (CLI) You can define a VMware vSphere PersistentVolumeClaim by creating a file, pvc.yaml , with the following contents: kind: PersistentVolumeClaim apiVersion: v1 metadata: name: pvc 1 spec: accessModes: - ReadWriteOnce 2 resources: requests: storage: 1Gi 3 1 A unique name that represents the persistent volume claim. 2 The access mode of the persistent volume claim. With ReadWriteOnce , the volume can be mounted with read and write permissions by a single node. 3 The size of the persistent volume claim. Enter the following command to create the PersistentVolumeClaim object from the file: USD oc create -f pvc.yaml 4.11.3. Statically provisioning VMware vSphere volumes To statically provision VMware vSphere volumes you must create the virtual machine disks for reference by the persistent volume framework. Prerequisites Storage must exist in the underlying infrastructure before it can be mounted as a volume in OpenShift Container Platform. Procedure Create the virtual machine disks. Virtual machine disks (VMDKs) must be created manually before statically provisioning VMware vSphere volumes. Use either of the following methods: Create using vmkfstools . Access ESX through Secure Shell (SSH) and then use following command to create a VMDK volume: USD vmkfstools -c <size> /vmfs/volumes/<datastore-name>/volumes/<disk-name>.vmdk Create using vmware-diskmanager : USD shell vmware-vdiskmanager -c -t 0 -s <size> -a lsilogic <disk-name>.vmdk Create a persistent volume that references the VMDKs. Create a file, pv1.yaml , with the PersistentVolume object definition: apiVersion: v1 kind: PersistentVolume metadata: name: pv1 1 spec: capacity: storage: 1Gi 2 accessModes: - ReadWriteOnce persistentVolumeReclaimPolicy: Retain vsphereVolume: 3 volumePath: "[datastore1] volumes/myDisk" 4 fsType: ext4 5 1 The name of the volume. This name is how it is identified by persistent volume claims or pods. 2 The amount of storage allocated to this volume. 3 The volume type used, with vsphereVolume for vSphere volumes. The label is used to mount a vSphere VMDK volume into pods. The contents of a volume are preserved when it is unmounted. The volume type supports VMFS and VSAN datastore. 4 The existing VMDK volume to use. If you used vmkfstools , you must enclose the datastore name in square brackets, [] , in the volume definition, as shown previously. 5 The file system type to mount. For example, ext4, xfs, or other file systems. Important Changing the value of the fsType parameter after the volume is formatted and provisioned can result in data loss and pod failure. Create the PersistentVolume object from the file: USD oc create -f pv1.yaml Create a persistent volume claim that maps to the persistent volume you created in the step. Create a file, pvc1.yaml , with the PersistentVolumeClaim object definition: apiVersion: v1 kind: PersistentVolumeClaim metadata: name: pvc1 1 spec: accessModes: - ReadWriteOnce 2 resources: requests: storage: "1Gi" 3 volumeName: pv1 4 1 A unique name that represents the persistent volume claim. 2 The access mode of the persistent volume claim. With ReadWriteOnce, the volume can be mounted with read and write permissions by a single node. 3 The size of the persistent volume claim. 4 The name of the existing persistent volume. Create the PersistentVolumeClaim object from the file: USD oc create -f pvc1.yaml 4.11.3.1. Formatting VMware vSphere volumes Before OpenShift Container Platform mounts the volume and passes it to a container, it checks that the volume contains a file system that is specified by the fsType parameter value in the PersistentVolume (PV) definition. If the device is not formatted with the file system, all data from the device is erased, and the device is automatically formatted with the specified file system. Because OpenShift Container Platform formats them before the first use, you can use unformatted vSphere volumes as PVs. 4.12. Persistent storage using local storage 4.12.1. Local storage overview You can use any of the following solutions to provision local storage: HostPath Provisioner (HPP) Local Storage Operator (LSO) Logical Volume Manager (LVM) Storage Warning These solutions support provisioning only node-local storage. The workloads are bound to the nodes that provide the storage. If the node becomes unavailable, the workload also becomes unavailable. To maintain workload availability despite node failures, you must ensure storage data replication through active or passive replication mechanisms. 4.12.1.1. Overview of HostPath Provisioner functionality You can perform the following actions using HostPath Provisioner (HPP): Map the host filesystem paths to storage classes for provisioning local storage. Statically create storage classes to configure filesystem paths on a node for storage consumption. Statically provision Persistent Volumes (PVs) based on the storage class. Create workloads and PersistentVolumeClaims (PVCs) while being aware of the underlying storage topology. Note HPP is available in upstream Kubernetes. However, it is not recommended to use HPP from upstream Kubernetes. 4.12.1.2. Overview of Local Storage Operator functionality You can perform the following actions using Local Storage Operator (LSO): Assign the storage devices (disks or partitions) to the storage classes without modifying the device configuration. Statically provision PVs and storage classes by configuring the LocalVolume custom resource (CR). Create workloads and PVCs while being aware of the underlying storage topology. Note LSO is developed and delivered by Red Hat. 4.12.1.3. Overview of LVM Storage functionality You can perform the following actions using Logical Volume Manager (LVM) Storage: Configure storage devices (disks or partitions) as lvm2 volume groups and expose the volume groups as storage classes. Create workloads and request storage by using PVCs without considering the node topology. LVM Storage uses the TopoLVM CSI driver to dynamically allocate storage space to the nodes in the topology and provision PVs. Note LVM Storage is developed and maintained by Red Hat. The CSI driver provided with LVM Storage is the upstream project "topolvm". 4.12.1.4. Comparison of LVM Storage, LSO, and HPP The following sections compare the functionalities provided by LVM Storage, Local Storage Operator (LSO), and HostPath Provisioner (HPP) to provision local storage. 4.12.1.4.1. Comparison of the support for storage types and filesystems The following table compares the support for storage types and filesystems provided by LVM Storage, Local Storage Operator (LSO), and HostPath Provisioner (HPP) to provision local storage: Table 4.1. Comparison of the support for storage types and filesystems Functionality LVM Storage LSO HPP Support for block storage Yes Yes No Support for file storage Yes Yes Yes Support for object storage [1] No No No Available filesystems ext4 , xfs ext4 , xfs Any mounted system available on the node is supported. None of the solutions (LVM Storage, LSO, and HPP) provide support for object storage. Therefore, if you want to use object storage, you need an S3 object storage solution, such as MultiClusterGateway from the Red Hat OpenShift Data Foundation. All of the solutions can serve as underlying storage providers for the S3 object storage solutions. 4.12.1.4.2. Comparison of the support for core functionalities The following table compares how LVM Storage, Local Storage Operator (LSO), and HostPath Provisioner (HPP) support core functionalities for provisioning local storage: Table 4.2. Comparison of the support for core functionalities Functionality LVM Storage LSO HPP Support for automatic file system formatting Yes Yes N/A Support for dynamic provisioning Yes No No Support for using software Redundant Array of Independent Disks (RAID) arrays Yes Supported on 4.15 and later. Yes Yes Support for transparent disk encryption Yes Supported on 4.16 and later. Yes Yes Support for volume based disk encryption No No No Support for disconnected installation Yes Yes Yes Support for PVC expansion Yes No No Support for volume snapshots and volume clones Yes No No Support for thin provisioning Yes Devices are thin-provisioned by default. Yes You can configure the devices to point to the thin-provisioned volumes Yes You can configure a path to point to the thin-provisioned volumes. Support for automatic disk discovery and setup Yes Automatic disk discovery is available during installation and runtime. You can also dynamically add the disks to the LVMCluster custom resource (CR) to increase the storage capacity of the existing storage classes. Technology Preview Automatic disk discovery is available during installation. No 4.12.1.4.3. Comparison of performance and isolation capabilities The following table compares the performance and isolation capabilities of LVM Storage, Local Storage Operator (LSO), and HostPath Provisioner (HPP) in provisioning local storage. Table 4.3. Comparison of performance and isolation capabilities Functionality LVM Storage LSO HPP Performance I/O speed is shared for all workloads that use the same storage class. Block storage allows direct I/O operations. Thin provisioning can affect the performance. I/O depends on the LSO configuration. Block storage allows direct I/O operations. I/O speed is shared for all workloads that use the same storage class. The restrictions imposed by the underlying filesystem can affect the I/O speed. Isolation boundary [1] LVM Logical Volume (LV) It provides higher level of isolation compared to HPP. LVM Logical Volume (LV) It provides higher level of isolation compared to HPP Filesystem path It provides lower level of isolation compared to LSO and LVM Storage. Isolation boundary refers to the level of separation between different workloads or applications that use local storage resources. 4.12.1.4.4. Comparison of the support for additional functionalities The following table compares the additional features provided by LVM Storage, Local Storage Operator (LSO), and HostPath Provisioner (HPP) to provision local storage: Table 4.4. Comparison of the support for additional functionalities Functionality LVM Storage LSO HPP Support for generic ephemeral volumes Yes No No Support for CSI inline ephemeral volumes No No No Support for storage topology Yes Supports CSI node topology Yes LSO provides partial support for storage topology through node tolerations. No Support for ReadWriteMany (RWX) access mode [1] No No No All of the solutions (LVM Storage, LSO, and HPP) have the ReadWriteOnce (RWO) access mode. RWO access mode allows access from multiple pods on the same node. 4.12.2. Persistent storage using local volumes OpenShift Container Platform can be provisioned with persistent storage by using local volumes. Local persistent volumes allow you to access local storage devices, such as a disk or partition, by using the standard persistent volume claim interface. Local volumes can be used without manually scheduling pods to nodes because the system is aware of the volume node constraints. However, local volumes are still subject to the availability of the underlying node and are not suitable for all applications. Note Local volumes can only be used as a statically created persistent volume. 4.12.2.1. Installing the Local Storage Operator The Local Storage Operator is not installed in OpenShift Container Platform by default. Use the following procedure to install and configure this Operator to enable local volumes in your cluster. Prerequisites Access to the OpenShift Container Platform web console or command-line interface (CLI). Procedure Create the openshift-local-storage project: USD oc adm new-project openshift-local-storage Optional: Allow local storage creation on infrastructure nodes. You might want to use the Local Storage Operator to create volumes on infrastructure nodes in support of components such as logging and monitoring. You must adjust the default node selector so that the Local Storage Operator includes the infrastructure nodes, and not just worker nodes. To block the Local Storage Operator from inheriting the cluster-wide default selector, enter the following command: USD oc annotate namespace openshift-local-storage openshift.io/node-selector='' Optional: Allow local storage to run on the management pool of CPUs in single-node deployment. Use the Local Storage Operator in single-node deployments and allow the use of CPUs that belong to the management pool. Perform this step on single-node installations that use management workload partitioning. To allow Local Storage Operator to run on the management CPU pool, run following commands: USD oc annotate namespace openshift-local-storage workload.openshift.io/allowed='management' From the UI To install the Local Storage Operator from the web console, follow these steps: Log in to the OpenShift Container Platform web console. Navigate to Operators OperatorHub . Type Local Storage into the filter box to locate the Local Storage Operator. Click Install . On the Install Operator page, select A specific namespace on the cluster . Select openshift-local-storage from the drop-down menu. Adjust the values for Update Channel and Approval Strategy to the values that you want. Click Install . Once finished, the Local Storage Operator will be listed in the Installed Operators section of the web console. From the CLI Install the Local Storage Operator from the CLI. Create an object YAML file to define an Operator group and subscription for the Local Storage Operator, such as openshift-local-storage.yaml : Example openshift-local-storage.yaml apiVersion: operators.coreos.com/v1 kind: OperatorGroup metadata: name: local-operator-group namespace: openshift-local-storage spec: targetNamespaces: - openshift-local-storage --- apiVersion: operators.coreos.com/v1alpha1 kind: Subscription metadata: name: local-storage-operator namespace: openshift-local-storage spec: channel: stable installPlanApproval: Automatic 1 name: local-storage-operator source: redhat-operators sourceNamespace: openshift-marketplace 1 The user approval policy for an install plan. Create the Local Storage Operator object by entering the following command: USD oc apply -f openshift-local-storage.yaml At this point, the Operator Lifecycle Manager (OLM) is now aware of the Local Storage Operator. A ClusterServiceVersion (CSV) for the Operator should appear in the target namespace, and APIs provided by the Operator should be available for creation. Verify local storage installation by checking that all pods and the Local Storage Operator have been created: Check that all the required pods have been created: USD oc -n openshift-local-storage get pods Example output NAME READY STATUS RESTARTS AGE local-storage-operator-746bf599c9-vlt5t 1/1 Running 0 19m Check the ClusterServiceVersion (CSV) YAML manifest to see that the Local Storage Operator is available in the openshift-local-storage project: USD oc get csvs -n openshift-local-storage Example output NAME DISPLAY VERSION REPLACES PHASE local-storage-operator.4.2.26-202003230335 Local Storage 4.2.26-202003230335 Succeeded After all checks have passed, the Local Storage Operator is installed successfully. 4.12.2.2. Provisioning local volumes by using the Local Storage Operator Local volumes cannot be created by dynamic provisioning. Instead, persistent volumes can be created by the Local Storage Operator. The local volume provisioner looks for any file system or block volume devices at the paths specified in the defined resource. Prerequisites The Local Storage Operator is installed. You have a local disk that meets the following conditions: It is attached to a node. It is not mounted. It does not contain partitions. Procedure Create the local volume resource. This resource must define the nodes and paths to the local volumes. Note Do not use different storage class names for the same device. Doing so will create multiple persistent volumes (PVs). Example: Filesystem apiVersion: "local.storage.openshift.io/v1" kind: "LocalVolume" metadata: name: "local-disks" namespace: "openshift-local-storage" 1 spec: nodeSelector: 2 nodeSelectorTerms: - matchExpressions: - key: kubernetes.io/hostname operator: In values: - ip-10-0-140-183 - ip-10-0-158-139 - ip-10-0-164-33 storageClassDevices: - storageClassName: "local-sc" 3 forceWipeDevicesAndDestroyAllData: false 4 volumeMode: Filesystem 5 fsType: xfs 6 devicePaths: 7 - /path/to/device 8 1 The namespace where the Local Storage Operator is installed. 2 Optional: A node selector containing a list of nodes where the local storage volumes are attached. This example uses the node hostnames, obtained from oc get node . If a value is not defined, then the Local Storage Operator will attempt to find matching disks on all available nodes. 3 The name of the storage class to use when creating persistent volume objects. The Local Storage Operator automatically creates the storage class if it does not exist. Be sure to use a storage class that uniquely identifies this set of local volumes. 4 This setting defines whether or not to call wipefs , which removes partition table signatures (magic strings) making the disk ready to use for Local Storage Operator (LSO) provisioning. No other data besides signatures is erased. The default is "false" ( wipefs is not invoked). Setting forceWipeDevicesAndDestroyAllData to "true" can be useful in scenarios where data can remain on disks that need to be re-used. In these scenarios, setting this field to true eliminates the need for administrators to erase the disks manually. Such cases can include single-node OpenShift (SNO) cluster environments where a node can be redeployed multiple times or when using OpenShift Data Foundation (ODF), where data can remain on the disks planned to be consumed as object storage devices (OSDs). 5 The volume mode, either Filesystem or Block , that defines the type of local volumes. Note A raw block volume ( volumeMode: Block ) is not formatted with a file system. Use this mode only if any application running on the pod can use raw block devices. 6 The file system that is created when the local volume is mounted for the first time. 7 The path containing a list of local storage devices to choose from. 8 Replace this value with your actual local disks filepath to the LocalVolume resource by-id , such as /dev/disk/by-id/wwn . PVs are created for these local disks when the provisioner is deployed successfully. Note If you are running OpenShift Container Platform with RHEL KVM, you must assign a serial number to your VM disk. Otherwise, the VM disk can not be identified after reboot. You can use the virsh edit <VM> command to add the <serial>mydisk</serial> definition. Example: Block apiVersion: "local.storage.openshift.io/v1" kind: "LocalVolume" metadata: name: "local-disks" namespace: "openshift-local-storage" 1 spec: nodeSelector: 2 nodeSelectorTerms: - matchExpressions: - key: kubernetes.io/hostname operator: In values: - ip-10-0-136-143 - ip-10-0-140-255 - ip-10-0-144-180 storageClassDevices: - storageClassName: "local-sc" 3 forceWipeDevicesAndDestroyAllData: false 4 volumeMode: Block 5 devicePaths: 6 - /path/to/device 7 1 The namespace where the Local Storage Operator is installed. 2 Optional: A node selector containing a list of nodes where the local storage volumes are attached. This example uses the node hostnames, obtained from oc get node . If a value is not defined, then the Local Storage Operator will attempt to find matching disks on all available nodes. 3 The name of the storage class to use when creating persistent volume objects. 4 This setting defines whether or not to call wipefs , which removes partition table signatures (magic strings) making the disk ready to use for Local Storage Operator (LSO) provisioning. No other data besides signatures is erased. The default is "false" ( wipefs is not invoked). Setting forceWipeDevicesAndDestroyAllData to "true" can be useful in scenarios where data can remain on disks that need to be re-used. In these scenarios, setting this field to true eliminates the need for administrators to erase the disks manually. Such cases can include single-node OpenShift (SNO) cluster environments where a node can be redeployed multiple times or when using OpenShift Data Foundation (ODF), where data can remain on the disks planned to be consumed as object storage devices (OSDs). 5 The volume mode, either Filesystem or Block , that defines the type of local volumes. 6 The path containing a list of local storage devices to choose from. 7 Replace this value with your actual local disks filepath to the LocalVolume resource by-id , such as dev/disk/by-id/wwn . PVs are created for these local disks when the provisioner is deployed successfully. Note If you are running OpenShift Container Platform with RHEL KVM, you must assign a serial number to your VM disk. Otherwise, the VM disk can not be identified after reboot. You can use the virsh edit <VM> command to add the <serial>mydisk</serial> definition. Create the local volume resource in your OpenShift Container Platform cluster. Specify the file you just created: USD oc create -f <local-volume>.yaml Verify that the provisioner was created and that the corresponding daemon sets were created: USD oc get all -n openshift-local-storage Example output NAME READY STATUS RESTARTS AGE pod/diskmaker-manager-9wzms 1/1 Running 0 5m43s pod/diskmaker-manager-jgvjp 1/1 Running 0 5m43s pod/diskmaker-manager-tbdsj 1/1 Running 0 5m43s pod/local-storage-operator-7db4bd9f79-t6k87 1/1 Running 0 14m NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE service/local-storage-operator-metrics ClusterIP 172.30.135.36 <none> 8383/TCP,8686/TCP 14m NAME DESIRED CURRENT READY UP-TO-DATE AVAILABLE NODE SELECTOR AGE daemonset.apps/diskmaker-manager 3 3 3 3 3 <none> 5m43s NAME READY UP-TO-DATE AVAILABLE AGE deployment.apps/local-storage-operator 1/1 1 1 14m NAME DESIRED CURRENT READY AGE replicaset.apps/local-storage-operator-7db4bd9f79 1 1 1 14m Note the desired and current number of daemon set processes. A desired count of 0 indicates that the label selectors were invalid. Verify that the persistent volumes were created: USD oc get pv Example output NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE local-pv-1cec77cf 100Gi RWO Delete Available local-sc 88m local-pv-2ef7cd2a 100Gi RWO Delete Available local-sc 82m local-pv-3fa1c73 100Gi RWO Delete Available local-sc 48m Important Editing the LocalVolume object does not change the fsType or volumeMode of existing persistent volumes because doing so might result in a destructive operation. 4.12.2.3. Provisioning local volumes without the Local Storage Operator Local volumes cannot be created by dynamic provisioning. Instead, persistent volumes can be created by defining the persistent volume (PV) in an object definition. The local volume provisioner looks for any file system or block volume devices at the paths specified in the defined resource. Important Manual provisioning of PVs includes the risk of potential data leaks across PV reuse when PVCs are deleted. The Local Storage Operator is recommended for automating the life cycle of devices when provisioning local PVs. Prerequisites Local disks are attached to the OpenShift Container Platform nodes. Procedure Define the PV. Create a file, such as example-pv-filesystem.yaml or example-pv-block.yaml , with the PersistentVolume object definition. This resource must define the nodes and paths to the local volumes. Note Do not use different storage class names for the same device. Doing so will create multiple PVs. example-pv-filesystem.yaml apiVersion: v1 kind: PersistentVolume metadata: name: example-pv-filesystem spec: capacity: storage: 100Gi volumeMode: Filesystem 1 accessModes: - ReadWriteOnce persistentVolumeReclaimPolicy: Delete storageClassName: local-sc 2 local: path: /dev/xvdf 3 nodeAffinity: required: nodeSelectorTerms: - matchExpressions: - key: kubernetes.io/hostname operator: In values: - example-node 1 The volume mode, either Filesystem or Block , that defines the type of PVs. 2 The name of the storage class to use when creating PV resources. Use a storage class that uniquely identifies this set of PVs. 3 The path containing a list of local storage devices to choose from, or a directory. You can only specify a directory with Filesystem volumeMode . Note A raw block volume ( volumeMode: block ) is not formatted with a file system. Use this mode only if any application running on the pod can use raw block devices. example-pv-block.yaml apiVersion: v1 kind: PersistentVolume metadata: name: example-pv-block spec: capacity: storage: 100Gi volumeMode: Block 1 accessModes: - ReadWriteOnce persistentVolumeReclaimPolicy: Delete storageClassName: local-sc 2 local: path: /dev/xvdf 3 nodeAffinity: required: nodeSelectorTerms: - matchExpressions: - key: kubernetes.io/hostname operator: In values: - example-node 1 The volume mode, either Filesystem or Block , that defines the type of PVs. 2 The name of the storage class to use when creating PV resources. Be sure to use a storage class that uniquely identifies this set of PVs. 3 The path containing a list of local storage devices to choose from. Create the PV resource in your OpenShift Container Platform cluster. Specify the file you just created: USD oc create -f <example-pv>.yaml Verify that the local PV was created: USD oc get pv Example output NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE example-pv-filesystem 100Gi RWO Delete Available local-sc 3m47s example-pv1 1Gi RWO Delete Bound local-storage/pvc1 local-sc 12h example-pv2 1Gi RWO Delete Bound local-storage/pvc2 local-sc 12h example-pv3 1Gi RWO Delete Bound local-storage/pvc3 local-sc 12h 4.12.2.4. Creating the local volume persistent volume claim Local volumes must be statically created as a persistent volume claim (PVC) to be accessed by the pod. Prerequisites Persistent volumes have been created using the local volume provisioner. Procedure Create the PVC using the corresponding storage class: kind: PersistentVolumeClaim apiVersion: v1 metadata: name: local-pvc-name 1 spec: accessModes: - ReadWriteOnce volumeMode: Filesystem 2 resources: requests: storage: 100Gi 3 storageClassName: local-sc 4 1 Name of the PVC. 2 The type of the PVC. Defaults to Filesystem . 3 The amount of storage available to the PVC. 4 Name of the storage class required by the claim. Create the PVC in the OpenShift Container Platform cluster, specifying the file you just created: USD oc create -f <local-pvc>.yaml 4.12.2.5. Attach the local claim After a local volume has been mapped to a persistent volume claim it can be specified inside of a resource. Prerequisites A persistent volume claim exists in the same namespace. Procedure Include the defined claim in the resource spec. The following example declares the persistent volume claim inside a pod: apiVersion: v1 kind: Pod spec: # ... containers: volumeMounts: - name: local-disks 1 mountPath: /data 2 volumes: - name: local-disks persistentVolumeClaim: claimName: local-pvc-name 3 # ... 1 The name of the volume to mount. 2 The path inside the pod where the volume is mounted. Do not mount to the container root, / , or any path that is the same in the host and the container. This can corrupt your host system if the container is sufficiently privileged, such as the host /dev/pts files. It is safe to mount the host by using /host . 3 The name of the existing persistent volume claim to use. Create the resource in the OpenShift Container Platform cluster, specifying the file you just created: USD oc create -f <local-pod>.yaml 4.12.2.6. Automating discovery and provisioning for local storage devices The Local Storage Operator automates local storage discovery and provisioning. With this feature, you can simplify installation when dynamic provisioning is not available during deployment, such as with bare metal, VMware, or AWS store instances with attached devices. Important Automatic discovery and provisioning is a Technology Preview feature only. Technology Preview features are not supported with Red Hat production service level agreements (SLAs) and might not be functionally complete. Red Hat does not recommend using them in production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process. For more information about the support scope of Red Hat Technology Preview features, see Technology Preview Features Support Scope . Important Automatic discovery and provisioning is fully supported when used to deploy Red Hat OpenShift Data Foundation on-premise or with platform-agnostic deployment. Use the following procedure to automatically discover local devices, and to automatically provision local volumes for selected devices. Warning Use the LocalVolumeSet object with caution. When you automatically provision persistent volumes (PVs) from local disks, the local PVs might claim all devices that match. If you are using a LocalVolumeSet object, make sure the Local Storage Operator is the only entity managing local devices on the node. Creating multiple instances of a LocalVolumeSet that target a node more than once is not supported. Prerequisites You have cluster administrator permissions. You have installed the Local Storage Operator. You have attached local disks to OpenShift Container Platform nodes. You have access to the OpenShift Container Platform web console and the oc command-line interface (CLI). Procedure To enable automatic discovery of local devices from the web console: Click Operators Installed Operators . In the openshift-local-storage namespace, click Local Storage . Click the Local Volume Discovery tab. Click Create Local Volume Discovery and then select either Form view or YAML view . Configure the LocalVolumeDiscovery object parameters. Click Create . The Local Storage Operator creates a local volume discovery instance named auto-discover-devices . To display a continuous list of available devices on a node: Log in to the OpenShift Container Platform web console. Navigate to Compute Nodes . Click the node name that you want to open. The "Node Details" page is displayed. Select the Disks tab to display the list of the selected devices. The device list updates continuously as local disks are added or removed. You can filter the devices by name, status, type, model, capacity, and mode. To automatically provision local volumes for the discovered devices from the web console: Navigate to Operators Installed Operators and select Local Storage from the list of Operators. Select Local Volume Set Create Local Volume Set . Enter a volume set name and a storage class name. Choose All nodes or Select nodes to apply filters accordingly. Note Only worker nodes are available, regardless of whether you filter using All nodes or Select nodes . Select the disk type, mode, size, and limit you want to apply to the local volume set, and click Create . A message displays after several minutes, indicating that the "Operator reconciled successfully." Alternatively, to provision local volumes for the discovered devices from the CLI: Create an object YAML file to define the local volume set, such as local-volume-set.yaml , as shown in the following example: apiVersion: local.storage.openshift.io/v1alpha1 kind: LocalVolumeSet metadata: name: example-autodetect spec: nodeSelector: nodeSelectorTerms: - matchExpressions: - key: kubernetes.io/hostname operator: In values: - worker-0 - worker-1 storageClassName: local-sc 1 volumeMode: Filesystem fsType: ext4 maxDeviceCount: 10 deviceInclusionSpec: deviceTypes: 2 - disk - part deviceMechanicalProperties: - NonRotational minSize: 10G maxSize: 100G models: - SAMSUNG - Crucial_CT525MX3 vendors: - ATA - ST2000LM 1 Determines the storage class that is created for persistent volumes that are provisioned from discovered devices. The Local Storage Operator automatically creates the storage class if it does not exist. Be sure to use a storage class that uniquely identifies this set of local volumes. 2 When using the local volume set feature, the Local Storage Operator does not support the use of logical volume management (LVM) devices. Create the local volume set object: USD oc apply -f local-volume-set.yaml Verify that the local persistent volumes were dynamically provisioned based on the storage class: USD oc get pv Example output NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE local-pv-1cec77cf 100Gi RWO Delete Available local-sc 88m local-pv-2ef7cd2a 100Gi RWO Delete Available local-sc 82m local-pv-3fa1c73 100Gi RWO Delete Available local-sc 48m Note Results are deleted after they are removed from the node. Symlinks must be manually removed. 4.12.2.7. Using tolerations with Local Storage Operator pods Taints can be applied to nodes to prevent them from running general workloads. To allow the Local Storage Operator to use tainted nodes, you must add tolerations to the Pod or DaemonSet definition. This allows the created resources to run on these tainted nodes. You apply tolerations to the Local Storage Operator pod through the LocalVolume resource and apply taints to a node through the node specification. A taint on a node instructs the node to repel all pods that do not tolerate the taint. Using a specific taint that is not on other pods ensures that the Local Storage Operator pod can also run on that node. Important Taints and tolerations consist of a key, value, and effect. As an argument, it is expressed as key=value:effect . An operator allows you to leave one of these parameters empty. Prerequisites The Local Storage Operator is installed. Local disks are attached to OpenShift Container Platform nodes with a taint. Tainted nodes are expected to provision local storage. Procedure To configure local volumes for scheduling on tainted nodes: Modify the YAML file that defines the Pod and add the LocalVolume spec, as shown in the following example: apiVersion: "local.storage.openshift.io/v1" kind: "LocalVolume" metadata: name: "local-disks" namespace: "openshift-local-storage" spec: tolerations: - key: localstorage 1 operator: Equal 2 value: "localstorage" 3 storageClassDevices: - storageClassName: "local-sc" volumeMode: Block 4 devicePaths: 5 - /dev/xvdg 1 Specify the key that you added to the node. 2 Specify the Equal operator to require the key / value parameters to match. If operator is Exists , the system checks that the key exists and ignores the value. If operator is Equal , then the key and value must match. 3 Specify the value local of the tainted node. 4 The volume mode, either Filesystem or Block , defining the type of the local volumes. 5 The path containing a list of local storage devices to choose from. Optional: To create local persistent volumes on only tainted nodes, modify the YAML file and add the LocalVolume spec, as shown in the following example: spec: tolerations: - key: node-role.kubernetes.io/master operator: Exists The defined tolerations will be passed to the resulting daemon sets, allowing the diskmaker and provisioner pods to be created for nodes that contain the specified taints. 4.12.2.8. Local Storage Operator Metrics OpenShift Container Platform provides the following metrics for the Local Storage Operator: lso_discovery_disk_count : total number of discovered devices on each node lso_lvset_provisioned_PV_count : total number of PVs created by LocalVolumeSet objects lso_lvset_unmatched_disk_count : total number of disks that Local Storage Operator did not select for provisioning because of mismatching criteria lso_lvset_orphaned_symlink_count : number of devices with PVs that no longer match LocalVolumeSet object criteria lso_lv_orphaned_symlink_count : number of devices with PVs that no longer match LocalVolume object criteria lso_lv_provisioned_PV_count : total number of provisioned PVs for LocalVolume To use these metrics, be sure to: Enable support for monitoring when installing the Local Storage Operator. When upgrading to OpenShift Container Platform 4.9 or later, enable metric support manually by adding the operator-metering=true label to the namespace. For more information about metrics, see Accessing metrics as an administrator . 4.12.2.9. Deleting the Local Storage Operator resources 4.12.2.9.1. Removing a local volume or local volume set Occasionally, local volumes and local volume sets must be deleted. While removing the entry in the resource and deleting the persistent volume is typically enough, if you want to reuse the same device path or have it managed by a different storage class, then additional steps are needed. Note The following procedure outlines an example for removing a local volume. The same procedure can also be used to remove symlinks for a local volume set custom resource. Prerequisites The persistent volume must be in a Released or Available state. Warning Deleting a persistent volume that is still in use can result in data loss or corruption. Procedure Edit the previously created local volume to remove any unwanted disks. Edit the cluster resource: USD oc edit localvolume <name> -n openshift-local-storage Navigate to the lines under devicePaths , and delete any representing unwanted disks. Delete any persistent volumes created. USD oc delete pv <pv-name> Delete directory and included symlinks on the node. Warning The following step involves accessing a node as the root user. Modifying the state of the node beyond the steps in this procedure could result in cluster instability. USD oc debug node/<node-name> -- chroot /host rm -rf /mnt/local-storage/<sc-name> 1 1 The name of the storage class used to create the local volumes. 4.12.2.9.2. Uninstalling the Local Storage Operator To uninstall the Local Storage Operator, you must remove the Operator and all created resources in the openshift-local-storage project. Warning Uninstalling the Local Storage Operator while local storage PVs are still in use is not recommended. While the PVs will remain after the Operator's removal, there might be indeterminate behavior if the Operator is uninstalled and reinstalled without removing the PVs and local storage resources. Prerequisites Access to the OpenShift Container Platform web console. Procedure Delete any local volume resources installed in the project, such as localvolume , localvolumeset , and localvolumediscovery : USD oc delete localvolume --all --all-namespaces USD oc delete localvolumeset --all --all-namespaces USD oc delete localvolumediscovery --all --all-namespaces Uninstall the Local Storage Operator from the web console. Log in to the OpenShift Container Platform web console. Navigate to Operators Installed Operators . Type Local Storage into the filter box to locate the Local Storage Operator. Click the Options menu at the end of the Local Storage Operator. Click Uninstall Operator . Click Remove in the window that appears. The PVs created by the Local Storage Operator will remain in the cluster until deleted. After these volumes are no longer in use, delete them by running the following command: USD oc delete pv <pv-name> Delete the openshift-local-storage project: USD oc delete project openshift-local-storage 4.12.3. Persistent storage using hostPath A hostPath volume in an OpenShift Container Platform cluster mounts a file or directory from the host node's filesystem into your pod. Most pods will not need a hostPath volume, but it does offer a quick option for testing should an application require it. Important The cluster administrator must configure pods to run as privileged. This grants access to pods in the same node. 4.12.3.1. Overview OpenShift Container Platform supports hostPath mounting for development and testing on a single-node cluster. In a production cluster, you would not use hostPath. Instead, a cluster administrator would provision a network resource, such as a GCE Persistent Disk volume, an NFS share, or an Amazon EBS volume. Network resources support the use of storage classes to set up dynamic provisioning. A hostPath volume must be provisioned statically. Important Do not mount to the container root, / , or any path that is the same in the host and the container. This can corrupt your host system if the container is sufficiently privileged. It is safe to mount the host by using /host . The following example shows the / directory from the host being mounted into the container at /host . apiVersion: v1 kind: Pod metadata: name: test-host-mount spec: containers: - image: registry.access.redhat.com/ubi9/ubi name: test-container command: ['sh', '-c', 'sleep 3600'] volumeMounts: - mountPath: /host name: host-slash volumes: - name: host-slash hostPath: path: / type: '' 4.12.3.2. Statically provisioning hostPath volumes A pod that uses a hostPath volume must be referenced by manual (static) provisioning. Procedure Define the persistent volume (PV) by creating a pv.yaml file with the PersistentVolume object definition: apiVersion: v1 kind: PersistentVolume metadata: name: task-pv-volume 1 labels: type: local spec: storageClassName: manual 2 capacity: storage: 5Gi accessModes: - ReadWriteOnce 3 persistentVolumeReclaimPolicy: Retain hostPath: path: "/mnt/data" 4 1 The name of the volume. This name is how the volume is identified by persistent volume (PV) claims or pods. 2 Used to bind persistent volume claim (PVC) requests to the PV. 3 The volume can be mounted as read-write by a single node. 4 The configuration file specifies that the volume is at /mnt/data on the cluster's node. To avoid corrupting your host system, do not mount to the container root, / , or any path that is the same in the host and the container. You can safely mount the host by using /host Create the PV from the file: USD oc create -f pv.yaml Define the PVC by creating a pvc.yaml file with the PersistentVolumeClaim object definition: apiVersion: v1 kind: PersistentVolumeClaim metadata: name: task-pvc-volume spec: accessModes: - ReadWriteOnce resources: requests: storage: 1Gi storageClassName: manual Create the PVC from the file: USD oc create -f pvc.yaml 4.12.3.3. Mounting the hostPath share in a privileged pod After the persistent volume claim has been created, it can be used inside by an application. The following example demonstrates mounting this share inside of a pod. Prerequisites A persistent volume claim exists that is mapped to the underlying hostPath share. Procedure Create a privileged pod that mounts the existing persistent volume claim: apiVersion: v1 kind: Pod metadata: name: pod-name 1 spec: containers: ... securityContext: privileged: true 2 volumeMounts: - mountPath: /data 3 name: hostpath-privileged ... securityContext: {} volumes: - name: hostpath-privileged persistentVolumeClaim: claimName: task-pvc-volume 4 1 The name of the pod. 2 The pod must run as privileged to access the node's storage. 3 The path to mount the host path share inside the privileged pod. Do not mount to the container root, / , or any path that is the same in the host and the container. This can corrupt your host system if the container is sufficiently privileged, such as the host /dev/pts files. It is safe to mount the host by using /host . 4 The name of the PersistentVolumeClaim object that has been previously created. 4.12.4. Persistent storage using Logical Volume Manager Storage Logical Volume Manager (LVM) Storage uses LVM2 through the TopoLVM CSI driver to dynamically provision local storage on a cluster with limited resources. You can create volume groups, persistent volume claims (PVCs), volume snapshots, and volume clones by using LVM Storage. 4.12.4.1. Logical Volume Manager Storage installation You can install Logical Volume Manager (LVM) Storage on an OpenShift Container Platform cluster and configure it to dynamically provision storage for your workloads. You can install LVM Storage by using the OpenShift Container Platform CLI ( oc ), OpenShift Container Platform web console, or Red Hat Advanced Cluster Management (RHACM). Warning When using LVM Storage on multi-node clusters, LVM Storage only supports provisioning local storage. LVM Storage does not support storage data replication mechanisms across nodes. You must ensure storage data replication through active or passive replication mechanisms to avoid a single point of failure. 4.12.4.1.1. Prerequisites to install LVM Storage The prerequisites to install LVM Storage are as follows: Ensure that you have a minimum of 10 milliCPU and 100 MiB of RAM. Ensure that every managed cluster has dedicated disks that are used to provision storage. LVM Storage uses only those disks that are empty and do not contain file system signatures. To ensure that the disks are empty and do not contain file system signatures, wipe the disks before using them. Before installing LVM Storage in a private CI environment where you can reuse the storage devices that you configured in the LVM Storage installation, ensure that you have wiped the disks that are not in use. If you do not wipe the disks before installing LVM Storage, you cannot reuse the disks without manual intervention. Note You cannot wipe the disks that are in use. If you want to install LVM Storage by using Red Hat Advanced Cluster Management (RHACM), ensure that you have installed RHACM on an OpenShift Container Platform cluster. See the "Installing LVM Storage using RHACM" section. Additional resources Red Hat Advanced Cluster Management for Kubernetes: Installing while connected online 4.12.4.1.2. Installing LVM Storage by using the CLI As a cluster administrator, you can install LVM Storage by using the OpenShift CLI. Prerequisites You have installed the OpenShift CLI ( oc ). You have logged in to OpenShift Container Platform as a user with cluster-admin and Operator installation permissions. Procedure Create a YAML file with the configuration for creating a namespace: Example YAML configuration for creating a namespace apiVersion: v1 kind: Namespace metadata: labels: openshift.io/cluster-monitoring: "true" pod-security.kubernetes.io/enforce: privileged pod-security.kubernetes.io/audit: privileged pod-security.kubernetes.io/warn: privileged name: openshift-storage Create the namespace by running the following command: USD oc create -f <file_name> Create an OperatorGroup CR YAML file: Example OperatorGroup CR apiVersion: operators.coreos.com/v1 kind: OperatorGroup metadata: name: openshift-storage-operatorgroup namespace: openshift-storage spec: targetNamespaces: - openshift-storage Create the OperatorGroup CR by running the following command: USD oc create -f <file_name> Create a Subscription CR YAML file: Example Subscription CR apiVersion: operators.coreos.com/v1alpha1 kind: Subscription metadata: name: lvms namespace: openshift-storage spec: installPlanApproval: Automatic name: lvms-operator source: redhat-operators sourceNamespace: openshift-marketplace Create the Subscription CR by running the following command: USD oc create -f <file_name> Verification To verify that LVM Storage is installed, run the following command: USD oc get csv -n openshift-storage -o custom-columns=Name:.metadata.name,Phase:.status.phase Example output Name Phase 4.13.0-202301261535 Succeeded 4.12.4.1.3. Installing LVM Storage by using the web console You can install LVM Storage by using the OpenShift Container Platform web console. Prerequisites You have access to the cluster. You have access to OpenShift Container Platform with cluster-admin and Operator installation permissions. Procedure Log in to the OpenShift Container Platform web console. Click Operators OperatorHub . Click LVM Storage on the OperatorHub page. Set the following options on the Operator Installation page: Update Channel as stable-4.17 . Installation Mode as A specific namespace on the cluster . Installed Namespace as Operator recommended namespace openshift-storage . If the openshift-storage namespace does not exist, it is created during the operator installation. Update approval as Automatic or Manual . Note If you select Automatic updates, the Operator Lifecycle Manager (OLM) automatically updates the running instance of LVM Storage without any intervention. If you select Manual updates, the OLM creates an update request. As a cluster administrator, you must manually approve the update request to update LVM Storage to a newer version. Optional: Select the Enable Operator recommended cluster monitoring on this Namespace checkbox. Click Install . Verification steps Verify that LVM Storage shows a green tick, indicating successful installation. 4.12.4.1.4. Installing LVM Storage in a disconnected environment You can install LVM Storage on OpenShift Container Platform in a disconnected environment. All sections referenced in this procedure are linked in the "Additional resources" section. Prerequisites You read the "About disconnected installation mirroring" section. You have access to the OpenShift Container Platform image repository. You created a mirror registry. Procedure Follow the steps in the "Creating the image set configuration" procedure. To create an ImageSetConfiguration custom resource (CR) for LVM Storage, you can use the following example ImageSetConfiguration CR configuration: Example ImageSetConfiguration CR for LVM Storage kind: ImageSetConfiguration apiVersion: mirror.openshift.io/v1alpha2 archiveSize: 4 1 storageConfig: 2 registry: imageURL: example.com/mirror/oc-mirror-metadata 3 skipTLS: false mirror: platform: channels: - name: stable-4.17 4 type: ocp graph: true 5 operators: - catalog: registry.redhat.io/redhat/redhat-operator-index:v4.17 6 packages: - name: lvms-operator 7 channels: - name: stable 8 additionalImages: - name: registry.redhat.io/ubi9/ubi:latest 9 helm: {} 1 Set the maximum size (in GiB) of each file within the image set. 2 Specify the location in which you want to save the image set. This location can be a registry or a local directory. You must configure the storageConfig field unless you are using the Technology Preview OCI feature. 3 Specify the storage URL for the image stream when using a registry. For more information, see Why use imagestreams . 4 Specify the channel from which you want to retrieve the OpenShift Container Platform images. 5 Set this field to true to generate the OpenShift Update Service (OSUS) graph image. For more information, see About the OpenShift Update Service . 6 Specify the Operator catalog from which you want to retrieve the OpenShift Container Platform images. 7 Specify the Operator packages to include in the image set. If this field is empty, all packages in the catalog are retrieved. 8 Specify the channels of the Operator packages to include in the image set. You must include the default channel for the Operator package even if you do not use the bundles in that channel. You can find the default channel by running the following command: USD oc mirror list operators --catalog=<catalog_name> --package=<package_name> . 9 Specify any additional images to include in the image set. Follow the procedure in the "Mirroring an image set to a mirror registry" section. Follow the procedure in the "Configuring image registry repository mirroring" section. Additional resources About disconnected installation mirroring Creating a mirror registry with mirror registry for Red Hat OpenShift Mirroring the OpenShift Container Platform image repository Creating the image set configuration Mirroring an image set to a mirror registry Configuring image registry repository mirroring Why use imagestreams 4.12.4.1.5. Installing LVM Storage by using RHACM To install LVM Storage on the clusters by using Red Hat Advanced Cluster Management (RHACM), you must create a Policy custom resource (CR). You can also configure the criteria to select the clusters on which you want to install LVM Storage. Note The Policy CR that is created to install LVM Storage is also applied to the clusters that are imported or created after creating the Policy CR. Prerequisites You have access to the RHACM cluster using an account with cluster-admin and Operator installation permissions. You have dedicated disks that LVM Storage can use on each cluster. The cluster must be managed by RHACM. Procedure Log in to the RHACM CLI using your OpenShift Container Platform credentials. Create a namespace. USD oc create ns <namespace> Create a Policy CR YAML file: Example Policy CR to install and configure LVM Storage apiVersion: apps.open-cluster-management.io/v1 kind: PlacementRule metadata: name: placement-install-lvms spec: clusterConditions: - status: "True" type: ManagedClusterConditionAvailable clusterSelector: 1 matchExpressions: - key: mykey operator: In values: - myvalue --- apiVersion: policy.open-cluster-management.io/v1 kind: PlacementBinding metadata: name: binding-install-lvms placementRef: apiGroup: apps.open-cluster-management.io kind: PlacementRule name: placement-install-lvms subjects: - apiGroup: policy.open-cluster-management.io kind: Policy name: install-lvms --- apiVersion: policy.open-cluster-management.io/v1 kind: Policy metadata: annotations: policy.open-cluster-management.io/categories: CM Configuration Management policy.open-cluster-management.io/controls: CM-2 Baseline Configuration policy.open-cluster-management.io/standards: NIST SP 800-53 name: install-lvms spec: disabled: false remediationAction: enforce policy-templates: - objectDefinition: apiVersion: policy.open-cluster-management.io/v1 kind: ConfigurationPolicy metadata: name: install-lvms spec: object-templates: - complianceType: musthave objectDefinition: 2 apiVersion: v1 kind: Namespace metadata: labels: openshift.io/cluster-monitoring: "true" pod-security.kubernetes.io/enforce: privileged pod-security.kubernetes.io/audit: privileged pod-security.kubernetes.io/warn: privileged name: openshift-storage - complianceType: musthave objectDefinition: 3 apiVersion: operators.coreos.com/v1 kind: OperatorGroup metadata: name: openshift-storage-operatorgroup namespace: openshift-storage spec: targetNamespaces: - openshift-storage - complianceType: musthave objectDefinition: 4 apiVersion: operators.coreos.com/v1alpha1 kind: Subscription metadata: name: lvms namespace: openshift-storage spec: installPlanApproval: Automatic name: lvms-operator source: redhat-operators sourceNamespace: openshift-marketplace remediationAction: enforce severity: low 1 Set the key field and values field in PlacementRule.spec.clusterSelector to match the labels that are configured in the clusters on which you want to install LVM Storage. 2 Namespace configuration. 3 The OperatorGroup CR configuration. 4 The Subscription CR configuration. Create the Policy CR by running the following command: USD oc create -f <file_name> -n <namespace> Upon creating the Policy CR, the following custom resources are created on the clusters that match the selection criteria configured in the PlacementRule CR: Namespace OperatorGroup Subscription Red Hat Advanced Cluster Management for Kubernetes: Installing while connected online About the LVMCluster custom resource 4.12.4.2. About the LVMCluster custom resource You can configure the LVMCluster CR to perform the following actions: Create LVM volume groups that you can use to provision persistent volume claims (PVCs). Configure a list of devices that you want to add to the LVM volume groups. Configure the requirements to select the nodes on which you want to create an LVM volume group, and the thin pool configuration for the volume group. Force wipe the selected devices. After you have installed LVM Storage, you must create an LVMCluster custom resource (CR). Example LVMCluster CR YAML file apiVersion: lvm.topolvm.io/v1alpha1 kind: LVMCluster metadata: name: my-lvmcluster spec: tolerations: - effect: NoSchedule key: xyz operator: Equal value: "true" storage: deviceClasses: - name: vg1 fstype: ext4 1 default: true nodeSelector: 2 nodeSelectorTerms: - matchExpressions: - key: mykey operator: In values: - ssd deviceSelector: 3 paths: - /dev/disk/by-path/pci-0000:87:00.0-nvme-1 - /dev/disk/by-path/pci-0000:88:00.0-nvme-1 optionalPaths: - /dev/disk/by-path/pci-0000:89:00.0-nvme-1 - /dev/disk/by-path/pci-0000:90:00.0-nvme-1 forceWipeDevicesAndDestroyAllData: true thinPoolConfig: name: thin-pool-1 sizePercent: 90 4 overprovisionRatio: 10 chunkSize: 128Ki 5 chunkSizeCalculationPolicy: Static 6 1 2 3 4 5 6 Optional field Explanation of fields in the LVMCluster CR The LVMCluster CR fields are described in the following table: Table 4.5. LVMCluster CR fields Field Type Description spec.storage.deviceClasses array Contains the configuration to assign the local storage devices to the LVM volume groups. LVM Storage creates a storage class and volume snapshot class for each device class that you create. deviceClasses.name string Specify a name for the LVM volume group (VG). You can also configure this field to reuse a volume group that you created in the installation. For more information, see "Reusing a volume group from the LVM Storage installation". deviceClasses.fstype string Set this field to ext4 or xfs . By default, this field is set to xfs . deviceClasses.default boolean Set this field to true to indicate that a device class is the default. Otherwise, you can set it to false . You can only configure a single default device class. deviceClasses.nodeSelector object Contains the configuration to choose the nodes on which you want to create the LVM volume group. If this field is empty, all nodes without no-schedule taints are considered. On the control-plane node, LVM Storage detects and uses the additional worker nodes when the new nodes become active in the cluster. nodeSelector.nodeSelectorTerms array Configure the requirements that are used to select the node. deviceClasses.deviceSelector object Contains the configuration to perform the following actions: Specify the paths to the devices that you want to add to the LVM volume group. Force wipe the devices that are added to the LVM volume group. For more information, see "About adding devices to a volume group". deviceSelector.paths array Specify the device paths. If the device path specified in this field does not exist, or the device is not supported by LVM Storage, the LVMCluster CR moves to the Failed state. deviceSelector.optionalPaths array Specify the optional device paths. If the device path specified in this field does not exist, or the device is not supported by LVM Storage, LVM Storage ignores the device without causing an error. deviceSelector. forceWipeDevicesAndDestroyAllData boolean LVM Storage uses only those disks that are empty and do not contain file system signatures. To ensure that the disks are empty and do not contain file system signatures, wipe the disks before using them. To force wipe the selected devices, set this field to true . By default, this field is set to false . Warning If this field is set to true , LVM Storage wipes all data on the devices. Use this feature with caution. Wiping the device can lead to inconsistencies in data integrity if any of the following conditions are met: The device is being used as swap space. The device is part of a RAID array. The device is mounted. If any of these conditions are true, do not force wipe the disk. Instead, you must manually wipe the disk. deviceClasses.thinPoolConfig object Contains the configuration to create a thin pool in the LVM volume group. If you exclude this field, logical volumes are thick provisioned. Using thick-provisioned storage includes the following limitations: No copy-on-write support for volume cloning. No support for snapshot class. No support for over-provisioning. As a result, the provisioned capacity of PersistentVolumeClaims (PVCs) is immediately reduced from the volume group. No support for thin metrics. Thick-provisioned devices only support volume group metrics. thinPoolConfig.name string Specify a name for the thin pool. thinPoolConfig.sizePercent integer Specify the percentage of space in the LVM volume group for creating the thin pool. By default, this field is set to 90. The minimum value that you can set is 10, and the maximum value is 90. thinPoolConfig.overprovisionRatio integer Specify a factor by which you can provision additional storage based on the available storage in the thin pool. For example, if this field is set to 10, you can provision up to 10 times the amount of available storage in the thin pool. To disable over-provisioning, set this field to 1. thinPoolConfig.chunkSize integer Specifies the statically calculated chunk size for the thin pool. This field is only used when the ChunkSizeCalculationPolicy field is set to Static . The value for this field must be configured in the range of 64 KiB to 1 GiB because of the underlying limitations of lvm2 . If you do not configure this field and the ChunkSizeCalculationPolicy field is set to Static , the default chunk size is set to 128 KiB. For more information, see "Overview of chunk size". thinPoolConfig.chunkSizeCalculationPolicy string Specifies the policy to calculate the chunk size for the underlying volume group. You can set this field to either Static or Host . By default, this field is set to Static . If this field is set to Static , the chunk size is set to the value of the chunkSize field. If the chunkSize field is not configured, chunk size is set to 128 KiB. If this field is set to Host , the chunk size is calculated based on the configuration in the lvm.conf file. For more information, see "Limitations to configure the size of the devices used in LVM Storage". Additional resources Overview of chunk size Limitations to configure the size of the devices used in LVM Storage Reusing a volume group from the LVM Storage installation About adding devices to a volume group Adding worker nodes to single-node OpenShift clusters 4.12.4.2.1. Limitations to configure the size of the devices used in LVM Storage The limitations to configure the size of the devices that you can use to provision storage using LVM Storage are as follows: The total storage size that you can provision is limited by the size of the underlying Logical Volume Manager (LVM) thin pool and the over-provisioning factor. The size of the logical volume depends on the size of the Physical Extent (PE) and the Logical Extent (LE). You can define the size of PE and LE during the physical and logical device creation. The default PE and LE size is 4 MB. If the size of the PE is increased, the maximum size of the LVM is determined by the kernel limits and your disk space. The following tables describe the chunk size and volume size limits for static and host configurations: Table 4.6. Tested configuration Parameter Value Chunk size 128 KiB Maximum volume size 32 TiB Table 4.7. Theoretical size limits for static configuration Parameter Minimum value Maximum value Chunk size 64 KiB 1 GiB Volume size Minimum size of the underlying Red Hat Enterprise Linux CoreOS (RHCOS) system. Maximum size of the underlying RHCOS system. Table 4.8. Theoretical size limits for a host configuration Parameter Value Chunk size This value is based on the configuration in the lvm.conf file. By default, this value is set to 128 KiB. Maximum volume size Equal to the maximum volume size of the underlying RHCOS system. Minimum volume size Equal to the minimum volume size of the underlying RHCOS system. 4.12.4.2.2. About adding devices to a volume group The deviceSelector field in the LVMCluster CR contains the configuration to specify the paths to the devices that you want to add to the Logical Volume Manager (LVM) volume group. You can specify the device paths in the deviceSelector.paths field, the deviceSelector.optionalPaths field, or both. If you do not specify the device paths in both the deviceSelector.paths field and the deviceSelector.optionalPaths field, LVM Storage adds the supported unused devices to the volume group (VG). Warning It is recommended to avoid referencing disks using symbolic naming, such as /dev/sdX , as these names may change across reboots within RHCOS. Instead, you must use stable naming schemes, such as /dev/disk/by-path/ or /dev/disk/by-id/ , to ensure consistent disk identification. With this change, you might need to adjust existing automation workflows in the cases where monitoring collects information about the install device for each node. For more information, see the RHEL documentation . You can add the path to the Redundant Array of Independent Disks (RAID) arrays in the deviceSelector field to integrate the RAID arrays with LVM Storage. You can create the RAID array by using the mdadm utility. LVM Storage does not support creating a software RAID. Note You can create a RAID array only during an OpenShift Container Platform installation. For information on creating a RAID array, see the following sections: "Configuring a RAID-enabled data volume" in "Additional resources". Creating a software RAID on an installed system Replacing a failed disk in RAID Repairing RAID disks You can also add encrypted devices to the volume group. You can enable disk encryption on the cluster nodes during an OpenShift Container Platform installation. After encrypting a device, you can specify the path to the LUKS encrypted device in the deviceSelector field. For information on disk encryption, see "About disk encryption" and "Configuring disk encryption and mirroring". The devices that you want to add to the VG must be supported by LVM Storage. For information about unsupported devices, see "Devices not supported by LVM Storage". LVM Storage adds the devices to the VG only if the following conditions are met: The device path exists. The device is supported by LVM Storage. Important After a device is added to the VG, you cannot remove the device. LVM Storage supports dynamic device discovery. If you do not add the deviceSelector field in the LVMCluster CR, LVM Storage automatically adds the new devices to the VG when the devices are available. Warning It is not recommended to add the devices to the VG through dynamic device discovery due to the following reasons: When you add a new device that you do not intend to add to the VG, LVM Storage automatically adds this device to the VG through dynamic device discovery. If LVM Storage adds a device to the VG through dynamic device discovery, LVM Storage does not restrict you from removing the device from the node. Removing or updating the devices that are already added to the VG can disrupt the VG. This can also lead to data loss and necessitate manual node remediation. Additional resources Configuring a RAID-enabled data volume About disk encryption Configuring disk encryption and mirroring Devices not supported by LVM Storage 4.12.4.2.3. Devices not supported by LVM Storage When you are adding the device paths in the deviceSelector field of the LVMCluster custom resource (CR), ensure that the devices are supported by LVM Storage. If you add paths to the unsupported devices, LVM Storage excludes the devices to avoid complexity in managing logical volumes. If you do not specify any device path in the deviceSelector field, LVM Storage adds only the unused devices that it supports. Note To get information about the devices, run the following command: USD lsblk --paths --json -o \ NAME,ROTA,TYPE,SIZE,MODEL,VENDOR,RO,STATE,KNAME,SERIAL,PARTLABEL,FSTYPE LVM Storage does not support the following devices: Read-only devices Devices with the ro parameter set to true . Suspended devices Devices with the state parameter set to suspended . ROM devices Devices with the type parameter set to rom . LVM partition devices Devices with the type parameter set to lvm . Devices with invalid partition labels Devices with the partlabel parameter set to bios , boot , or reserved . Devices with an invalid filesystem Devices with the fstype parameter set to any value other than null or LVM2_member . Important LVM Storage supports devices with fstype parameter set to LVM2_member only if the devices do not contain children devices. Devices that are part of another volume group To get the information about the volume groups of the device, run the following command: USD pvs <device-name> 1 1 Replace <device-name> with the device name. Devices with bind mounts To get the mount points of a device, run the following command: USD cat /proc/1/mountinfo | grep <device-name> 1 1 Replace <device-name> with the device name. Devices that contain children devices Note It is recommended to wipe the device before using it in LVM Storage to prevent unexpected behavior. 4.12.4.3. Ways to create an LVMCluster custom resource You can create an LVMCluster custom resource (CR) by using the OpenShift CLI ( oc ) or the OpenShift Container Platform web console. If you have installed LVM Storage by using Red Hat Advanced Cluster Management (RHACM), you can also create an LVMCluster CR by using RHACM. Upon creating the LVMCluster CR, LVM Storage creates the following system-managed CRs: A storageClass and volumeSnapshotClass for each device class. Note LVM Storage configures the name of the storage class and volume snapshot class in the format lvms-<device_class_name> , where, <device_class_name> is the value of the deviceClasses.name field in the LVMCluster CR. For example, if the deviceClasses.name field is set to vg1, the name of the storage class and volume snapshot class is lvms-vg1 . LVMVolumeGroup : This CR is a specific type of persistent volume (PV) that is backed by an LVM volume group. It tracks the individual volume groups across multiple nodes. LVMVolumeGroupNodeStatus : This CR tracks the status of the volume groups on a node. 4.12.4.3.1. Reusing a volume group from the LVM Storage installation You can reuse an existing volume group (VG) from the LVM Storage installation instead of creating a new VG. You can only reuse a VG but not the logical volume associated with the VG. Important You can perform this procedure only while creating an LVMCluster custom resource (CR). Prerequisites The VG that you want to reuse must not be corrupted. The VG that you want to reuse must have the lvms tag. For more information on adding tags to LVM objects, see Grouping LVM objects with tags . Procedure Open the LVMCluster CR YAML file. Configure the LVMCluster CR parameters as described in the following example: Example LVMCluster CR YAML file apiVersion: lvm.topolvm.io/v1alpha1 kind: LVMCluster metadata: name: my-lvmcluster spec: # ... storage: deviceClasses: - name: vg1 1 fstype: ext4 2 default: true deviceSelector: 3 # ... forceWipeDevicesAndDestroyAllData: false 4 thinPoolConfig: 5 # ... nodeSelector: 6 # ... 1 Set this field to the name of a VG from the LVM Storage installation. 2 Set this field to ext4 or xfs . By default, this field is set to xfs . 3 You can add new devices to the VG that you want to reuse by specifying the new device paths in the deviceSelector field. If you do not want to add new devices to the VG, ensure that the deviceSelector configuration in the current LVM Storage installation is same as that of the LVM Storage installation. 4 If this field is set to true , LVM Storage wipes all the data on the devices that are added to the VG. 5 To retain the thinPoolConfig configuration of the VG that you want to reuse, ensure that the thinPoolConfig configuration in the current LVM Storage installation is same as that of the LVM Storage installation. Otherwise, you can configure the thinPoolConfig field as required. 6 Configure the requirements to choose the nodes on which you want to create the LVM volume group. If this field is empty, all nodes without no-schedule taints are considered. Save the LVMCluster CR YAML file. Note To view the devices that are part a volume group, run the following command: USD pvs -S vgname=<vg_name> 1 1 Replace <vg_name> with the name of the volume group. 4.12.4.3.2. Creating an LVMCluster CR by using the CLI You can create an LVMCluster custom resource (CR) on a worker node using the OpenShift CLI ( oc ). Important You can only create a single instance of the LVMCluster custom resource (CR) on an OpenShift Container Platform cluster. Prerequisites You have installed the OpenShift CLI ( oc ). You have logged in to OpenShift Container Platform as a user with cluster-admin privileges. You have installed LVM Storage. You have installed a worker node in the cluster. You read the "About the LVMCluster custom resource" section. Procedure Create an LVMCluster custom resource (CR) YAML file: Example LVMCluster CR YAML file apiVersion: lvm.topolvm.io/v1alpha1 kind: LVMCluster metadata: name: my-lvmcluster spec: # ... storage: deviceClasses: 1 # ... nodeSelector: 2 # ... deviceSelector: 3 # ... thinPoolConfig: 4 # ... 1 Contains the configuration to assign the local storage devices to the LVM volume groups. 2 Contains the configuration to choose the nodes on which you want to create the LVM volume group. If this field is empty, all nodes without no-schedule taints are considered. 3 Contains the configuration to specify the paths to the devices that you want to add to the LVM volume group, and force wipe the devices that are added to the LVM volume group. 4 Contains the configuration to create a thin pool in the LVM volume group. If you exclude this field, logical volumes are thick provisioned. Create the LVMCluster CR by running the following command: USD oc create -f <file_name> Example output lvmcluster/lvmcluster created Verification Check that the LVMCluster CR is in the Ready state: USD oc get lvmclusters.lvm.topolvm.io -o jsonpath='{.items[*].status}' -n <namespace> Example output {"deviceClassStatuses": 1 [ { "name": "vg1", "nodeStatus": [ 2 { "devices": [ 3 "/dev/nvme0n1", "/dev/nvme1n1", "/dev/nvme2n1" ], "node": "kube-node", 4 "status": "Ready" 5 } ] } ] "state":"Ready"} 6 1 The status of the device class. 2 The status of the LVM volume group on each node. 3 The list of devices used to create the LVM volume group. 4 The node on which the device class is created. 5 The status of the LVM volume group on the node. 6 The status of the LVMCluster CR. Note If the LVMCluster CR is in the Failed state, you can view the reason for failure in the status field. Example of status field with the reason for failue: status: deviceClassStatuses: - name: vg1 nodeStatus: - node: my-node-1.example.com reason: no available devices found for volume group status: Failed state: Failed Optional: To view the storage classes created by LVM Storage for each device class, run the following command: USD oc get storageclass Example output NAME PROVISIONER RECLAIMPOLICY VOLUMEBINDINGMODE ALLOWVOLUMEEXPANSION AGE lvms-vg1 topolvm.io Delete WaitForFirstConsumer true 31m Optional: To view the volume snapshot classes created by LVM Storage for each device class, run the following command: USD oc get volumesnapshotclass Example output NAME DRIVER DELETIONPOLICY AGE lvms-vg1 topolvm.io Delete 24h Additional resources About the LVMCluster custom resource 4.12.4.3.3. Creating an LVMCluster CR by using the web console You can create an LVMCluster CR on a worker node using the OpenShift Container Platform web console. Important You can only create a single instance of the LVMCluster custom resource (CR) on an OpenShift Container Platform cluster. Prerequisites You have access to the OpenShift Container Platform cluster with cluster-admin privileges. You have installed LVM Storage. You have installed a worker node in the cluster. You read the "About the LVMCluster custom resource" section. Procedure Log in to the OpenShift Container Platform web console. Click Operators Installed Operators . In the openshift-storage namespace, click LVM Storage . Click Create LVMCluster and select either Form view or YAML view . Configure the required LVMCluster CR parameters. Click Create . Optional: If you want to edit the LVMCLuster CR, perform the following actions: Click the LVMCluster tab. From the Actions menu, select Edit LVMCluster . Click YAML and edit the required LVMCLuster CR parameters. Click Save . Verification On the LVMCLuster page, check that the LVMCluster CR is in the Ready state. Optional: To view the available storage classes created by LVM Storage for each device class, click Storage StorageClasses . Optional: To view the available volume snapshot classes created by LVM Storage for each device class, click Storage VolumeSnapshotClasses . Additional resources About the LVMCluster custom resource 4.12.4.3.4. Creating an LVMCluster CR by using RHACM After you have installed LVM Storage by using RHACM, you must create an LVMCluster custom resource (CR). Prerequisites You have installed LVM Storage by using RHACM. You have access to the RHACM cluster using an account with cluster-admin permissions. You read the "About the LVMCluster custom resource" section. Procedure Log in to the RHACM CLI using your OpenShift Container Platform credentials. Create a ConfigurationPolicy CR YAML file with the configuration to create an LVMCluster CR: Example ConfigurationPolicy CR YAML file to create an LVMCluster CR apiVersion: policy.open-cluster-management.io/v1 kind: ConfigurationPolicy metadata: name: lvms spec: object-templates: - complianceType: musthave objectDefinition: apiVersion: lvm.topolvm.io/v1alpha1 kind: LVMCluster metadata: name: my-lvmcluster namespace: openshift-storage spec: storage: deviceClasses: 1 # ... deviceSelector: 2 # ... thinPoolConfig: 3 # ... nodeSelector: 4 # ... remediationAction: enforce severity: low 1 Contains the configuration to assign the local storage devices to the LVM volume groups. 2 Contains the configuration to specify the paths to the devices that you want to add to the LVM volume group, and force wipe the devices that are added to the LVM volume group. 3 Contains the configuration to create a thin pool in the LVM volume group. If you exclude this field, logical volumes are thick provisioned. 4 Contains the configuration to choose the nodes on which you want to create the LVM volume groups. If this field is empty, then all nodes without no-schedule taints are considered. Create the ConfigurationPolicy CR by running the following command: USD oc create -f <file_name> -n <cluster_namespace> 1 1 Namespace of the OpenShift Container Platform cluster on which LVM Storage is installed. Additional resources Red Hat Advanced Cluster Management for Kubernetes: Installing while connected online About the LVMCluster custom resource 4.12.4.4. Ways to delete an LVMCluster custom resource You can delete an LVMCluster custom resource (CR) by using the OpenShift CLI ( oc ) or the OpenShift Container Platform web console. If you have installed LVM Storage by using Red Hat Advanced Cluster Management (RHACM), you can also delete an LVMCluster CR by using RHACM. Upon deleting the LVMCluster CR, LVM Storage deletes the following CRs: storageClass volumeSnapshotClass LVMVolumeGroup LVMVolumeGroupNodeStatus 4.12.4.4.1. Deleting an LVMCluster CR by using the CLI You can delete the LVMCluster custom resource (CR) using the OpenShift CLI ( oc ). Prerequisites You have access to OpenShift Container Platform as a user with cluster-admin permissions. You have deleted the persistent volume claims (PVCs), volume snapshots, and volume clones provisioned by LVM Storage. You have also deleted the applications that are using these resources. Procedure Log in to the OpenShift CLI ( oc ). Delete the LVMCluster CR by running the following command: USD oc delete lvmcluster <lvmclustername> -n openshift-storage Verification To verify that the LVMCluster CR has been deleted, run the following command: USD oc get lvmcluster -n <namespace> Example output No resources found in openshift-storage namespace. 4.12.4.4.2. Deleting an LVMCluster CR by using the web console You can delete the LVMCluster custom resource (CR) using the OpenShift Container Platform web console. Prerequisites You have access to OpenShift Container Platform as a user with cluster-admin permissions. You have deleted the persistent volume claims (PVCs), volume snapshots, and volume clones provisioned by LVM Storage. You have also deleted the applications that are using these resources. Procedure Log in to the OpenShift Container Platform web console. Click Operators Installed Operators to view all the installed Operators. Click LVM Storage in the openshift-storage namespace. Click the LVMCluster tab. From the Actions , select Delete LVMCluster . Click Delete . Verification On the LVMCLuster page, check that the LVMCluster CR has been deleted. 4.12.4.4.3. Deleting an LVMCluster CR by using RHACM If you have installed LVM Storage by using Red Hat Advanced Cluster Management (RHACM), you can delete an LVMCluster CR by using RHACM. Prerequisites You have access to the RHACM cluster as a user with cluster-admin permissions. You have deleted the persistent volume claims (PVCs), volume snapshots, and volume clones provisioned by LVM Storage. You have also deleted the applications that are using these resources. Procedure Log in to the RHACM CLI using your OpenShift Container Platform credentials. Delete the ConfigurationPolicy CR YAML file that was created for the LVMCluster CR: USD oc delete -f <file_name> -n <cluster_namespace> 1 1 Namespace of the OpenShift Container Platform cluster on which LVM Storage is installed. Create a Policy CR YAML file to delete the LVMCluster CR: Example Policy CR to delete the LVMCluster CR apiVersion: policy.open-cluster-management.io/v1 kind: Policy metadata: name: policy-lvmcluster-delete annotations: policy.open-cluster-management.io/standards: NIST SP 800-53 policy.open-cluster-management.io/categories: CM Configuration Management policy.open-cluster-management.io/controls: CM-2 Baseline Configuration spec: remediationAction: enforce disabled: false policy-templates: - objectDefinition: apiVersion: policy.open-cluster-management.io/v1 kind: ConfigurationPolicy metadata: name: policy-lvmcluster-removal spec: remediationAction: enforce 1 severity: low object-templates: - complianceType: mustnothave objectDefinition: kind: LVMCluster apiVersion: lvm.topolvm.io/v1alpha1 metadata: name: my-lvmcluster namespace: openshift-storage 2 --- apiVersion: policy.open-cluster-management.io/v1 kind: PlacementBinding metadata: name: binding-policy-lvmcluster-delete placementRef: apiGroup: apps.open-cluster-management.io kind: PlacementRule name: placement-policy-lvmcluster-delete subjects: - apiGroup: policy.open-cluster-management.io kind: Policy name: policy-lvmcluster-delete --- apiVersion: apps.open-cluster-management.io/v1 kind: PlacementRule metadata: name: placement-policy-lvmcluster-delete spec: clusterConditions: - status: "True" type: ManagedClusterConditionAvailable clusterSelector: 3 matchExpressions: - key: mykey operator: In values: - myvalue 1 The spec.remediationAction in policy-template is overridden by the preceding parameter value for spec.remediationAction . 2 This namespace field must have the openshift-storage value. 3 Configure the requirements to select the clusters. LVM Storage is uninstalled on the clusters that match the selection criteria. Create the Policy CR by running the following command: USD oc create -f <file_name> -n <namespace> Create a Policy CR YAML file to check if the LVMCluster CR has been deleted: Example Policy CR to check if the LVMCluster CR has been deleted apiVersion: policy.open-cluster-management.io/v1 kind: Policy metadata: name: policy-lvmcluster-inform annotations: policy.open-cluster-management.io/standards: NIST SP 800-53 policy.open-cluster-management.io/categories: CM Configuration Management policy.open-cluster-management.io/controls: CM-2 Baseline Configuration spec: remediationAction: inform disabled: false policy-templates: - objectDefinition: apiVersion: policy.open-cluster-management.io/v1 kind: ConfigurationPolicy metadata: name: policy-lvmcluster-removal-inform spec: remediationAction: inform 1 severity: low object-templates: - complianceType: mustnothave objectDefinition: kind: LVMCluster apiVersion: lvm.topolvm.io/v1alpha1 metadata: name: my-lvmcluster namespace: openshift-storage 2 --- apiVersion: policy.open-cluster-management.io/v1 kind: PlacementBinding metadata: name: binding-policy-lvmcluster-check placementRef: apiGroup: apps.open-cluster-management.io kind: PlacementRule name: placement-policy-lvmcluster-check subjects: - apiGroup: policy.open-cluster-management.io kind: Policy name: policy-lvmcluster-inform --- apiVersion: apps.open-cluster-management.io/v1 kind: PlacementRule metadata: name: placement-policy-lvmcluster-check spec: clusterConditions: - status: "True" type: ManagedClusterConditionAvailable clusterSelector: matchExpressions: - key: mykey operator: In values: - myvalue 1 The policy-template spec.remediationAction is overridden by the preceding parameter value for spec.remediationAction . 2 The namespace field must have the openshift-storage value. Create the Policy CR by running the following command: USD oc create -f <file_name> -n <namespace> Verification Check the status of the Policy CRs by running the following command: USD oc get policy -n <namespace> Example output NAME REMEDIATION ACTION COMPLIANCE STATE AGE policy-lvmcluster-delete enforce Compliant 15m policy-lvmcluster-inform inform Compliant 15m Important The Policy CRs must be in Compliant state. 4.12.4.5. Provisioning storage After you have created the LVM volume groups using the LVMCluster custom resource (CR), you can provision the storage by creating persistent volume claims (PVCs). The following are the minimum storage sizes that you can request for each file system type: block : 8 MiB xfs : 300 MiB ext4 : 32 MiB To create a PVC, you must create a PersistentVolumeClaim object. Prerequisites You have created an LVMCluster CR. Procedure Log in to the OpenShift CLI ( oc ). Create a PersistentVolumeClaim object: Example PersistentVolumeClaim object apiVersion: v1 kind: PersistentVolumeClaim metadata: name: lvm-block-1 1 namespace: default spec: accessModes: - ReadWriteOnce volumeMode: Block 2 resources: requests: storage: 10Gi 3 limits: storage: 20Gi 4 storageClassName: lvms-vg1 5 1 Specify a name for the PVC. 2 To create a block PVC, set this field to Block . To create a file PVC, set this field to Filesystem . 3 Specify the storage size. If the value is less than the minimum storage size, the requested storage size is rounded to the minimum storage size. The total storage size you can provision is limited by the size of the Logical Volume Manager (LVM) thin pool and the over-provisioning factor. 4 Optional: Specify the storage limit. Set this field to a value that is greater than or equal to the minimum storage size. Otherwise, PVC creation fails with an error. 5 The value of the storageClassName field must be in the format lvms-<device_class_name> where <device_class_name> is the value of the deviceClasses.name field in the LVMCluster CR. For example, if the deviceClasses.name field is set to vg1 , you must set the storageClassName field to lvms-vg1 . Note The volumeBindingMode field of the storage class is set to WaitForFirstConsumer . Create the PVC by running the following command: # oc create -f <file_name> -n <application_namespace> Note The created PVCs remain in Pending state until you deploy the pods that use them. Verification To verify that the PVC is created, run the following command: USD oc get pvc -n <namespace> Example output NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE lvm-block-1 Bound pvc-e90169a8-fd71-4eea-93b8-817155f60e47 1Gi RWO lvms-vg1 5s 4.12.4.6. Ways to scale up the storage of clusters OpenShift Container Platform supports additional worker nodes for clusters on bare metal user-provisioned infrastructure. You can scale up the storage of clusters either by adding new worker nodes with available storage or by adding new devices to the existing worker nodes. Logical Volume Manager (LVM) Storage detects and uses additional worker nodes when the nodes become active. To add a new device to the existing worker nodes on a cluster, you must add the path to the new device in the deviceSelector field of the LVMCluster custom resource (CR). Important You can add the deviceSelector field in the LVMCluster CR only while creating the LVMCluster CR. If you have not added the deviceSelector field while creating the LVMCluster CR, you must delete the LVMCluster CR and create a new LVMCluster CR containing the deviceSelector field. If you do not add the deviceSelector field in the LVMCluster CR, LVM Storage automatically adds the new devices when the devices are available. Note LVM Storage adds only the supported devices. For information about unsupported devices, see "Devices not supported by LVM Storage". Additional resources Adding worker nodes to single-node OpenShift clusters Devices not supported by LVM Storage 4.12.4.6.1. Scaling up the storage of clusters by using the CLI You can scale up the storage capacity of the worker nodes on a cluster by using the OpenShift CLI ( oc ). Prerequisites You have additional unused devices on each cluster to be used by Logical Volume Manager (LVM) Storage. You have installed the OpenShift CLI ( oc ). You have created an LVMCluster custom resource (CR). Procedure Edit the LVMCluster CR by running the following command: USD oc edit <lvmcluster_file_name> -n <namespace> Add the path to the new device in the deviceSelector field. Example LVMCluster CR apiVersion: lvm.topolvm.io/v1alpha1 kind: LVMCluster metadata: name: my-lvmcluster spec: storage: deviceClasses: # ... deviceSelector: 1 paths: 2 - /dev/disk/by-path/pci-0000:87:00.0-nvme-1 - /dev/disk/by-path/pci-0000:88:00.0-nvme-1 optionalPaths: 3 - /dev/disk/by-path/pci-0000:89:00.0-nvme-1 - /dev/disk/by-path/pci-0000:90:00.0-nvme-1 # ... 1 Contains the configuration to specify the paths to the devices that you want to add to the LVM volume group. You can specify the device paths in the paths field, the optionalPaths field, or both. If you do not specify the device paths in both paths and optionalPaths , Logical Volume Manager (LVM) Storage adds the supported unused devices to the LVM volume group. LVM Storage adds the devices to the LVM volume group only if the following conditions are met: The device path exists. The device is supported by LVM Storage. For information about unsupported devices, see "Devices not supported by LVM Storage". 2 Specify the device paths. If the device path specified in this field does not exist, or the device is not supported by LVM Storage, the LVMCluster CR moves to the Failed state. 3 Specify the optional device paths. If the device path specified in this field does not exist, or the device is not supported by LVM Storage, LVM Storage ignores the device without causing an error. Important After a device is added to the LVM volume group, it cannot be removed. Save the LVMCluster CR. Additional resources About the LVMCluster custom resource Devices not supported by LVM Storage About adding devices to a volume group 4.12.4.6.2. Scaling up the storage of clusters by using the web console You can scale up the storage capacity of the worker nodes on a cluster by using the OpenShift Container Platform web console. Prerequisites You have additional unused devices on each cluster to be used by Logical Volume Manager (LVM) Storage. You have created an LVMCluster custom resource (CR). Procedure Log in to the OpenShift Container Platform web console. Click Operators Installed Operators . Click LVM Storage in the openshift-storage namespace. Click the LVMCluster tab to view the LVMCluster CR created on the cluster. From the Actions menu, select Edit LVMCluster . Click the YAML tab. Edit the LVMCluster CR to add the new device path in the deviceSelector field: Example LVMCluster CR apiVersion: lvm.topolvm.io/v1alpha1 kind: LVMCluster metadata: name: my-lvmcluster spec: storage: deviceClasses: # ... deviceSelector: 1 paths: 2 - /dev/disk/by-path/pci-0000:87:00.0-nvme-1 - /dev/disk/by-path/pci-0000:88:00.0-nvme-1 optionalPaths: 3 - /dev/disk/by-path/pci-0000:89:00.0-nvme-1 - /dev/disk/by-path/pci-0000:90:00.0-nvme-1 # ... 1 Contains the configuration to specify the paths to the devices that you want to add to the LVM volume group. You can specify the device paths in the paths field, the optionalPaths field, or both. If you do not specify the device paths in both paths and optionalPaths , Logical Volume Manager (LVM) Storage adds the supported unused devices to the LVM volume group. LVM Storage adds the devices to the LVM volume group only if the following conditions are met: The device path exists. The device is supported by LVM Storage. For information about unsupported devices, see "Devices not supported by LVM Storage". 2 Specify the device paths. If the device path specified in this field does not exist, or the device is not supported by LVM Storage, the LVMCluster CR moves to the Failed state. 3 Specify the optional device paths. If the device path specified in this field does not exist, or the device is not supported by LVM Storage, LVM Storage ignores the device without causing an error. Important After a device is added to the LVM volume group, it cannot be removed. Click Save . Additional resources About the LVMCluster custom resource Devices not supported by LVM Storage About adding devices to a volume group 4.12.4.6.3. Scaling up the storage of clusters by using RHACM You can scale up the storage capacity of worker nodes on the clusters by using RHACM. Prerequisites You have access to the RHACM cluster using an account with cluster-admin privileges. You have created an LVMCluster custom resource (CR) by using RHACM. You have additional unused devices on each cluster to be used by Logical Volume Manager (LVM) Storage. Procedure Log in to the RHACM CLI using your OpenShift Container Platform credentials. Edit the LVMCluster CR that you created using RHACM by running the following command: USD oc edit -f <file_name> -ns <namespace> 1 1 Replace <file_name> with the name of the LVMCluster CR. In the LVMCluster CR, add the path to the new device in the deviceSelector field. Example LVMCluster CR apiVersion: policy.open-cluster-management.io/v1 kind: ConfigurationPolicy metadata: name: lvms spec: object-templates: - complianceType: musthave objectDefinition: apiVersion: lvm.topolvm.io/v1alpha1 kind: LVMCluster metadata: name: my-lvmcluster namespace: openshift-storage spec: storage: deviceClasses: # ... deviceSelector: 1 paths: 2 - /dev/disk/by-path/pci-0000:87:00.0-nvme-1 optionalPaths: 3 - /dev/disk/by-path/pci-0000:89:00.0-nvme-1 # ... 1 Contains the configuration to specify the paths to the devices that you want to add to the LVM volume group. You can specify the device paths in the paths field, the optionalPaths field, or both. If you do not specify the device paths in both paths and optionalPaths , Logical Volume Manager (LVM) Storage adds the supported unused devices to the LVM volume group. LVM Storage adds the devices to the LVM volume group only if the following conditions are met: The device path exists. The device is supported by LVM Storage. For information about unsupported devices, see "Devices not supported by LVM Storage". 2 Specify the device paths. If the device path specified in this field does not exist, or the device is not supported by LVM Storage, the LVMCluster CR moves to the Failed state. 3 Specify the optional device paths. If the device path specified in this field does not exist, or the device is not supported by LVM Storage, LVM Storage ignores the device without causing an error. Important After a device is added to the LVM volume group, it cannot be removed. Save the LVMCluster CR. Additional resources Red Hat Advanced Cluster Management for Kubernetes: Installing while connected online About the LVMCluster custom resource Devices not supported by LVM Storage About adding devices to a volume group 4.12.4.7. Expanding a persistent volume claim After scaling up the storage of a cluster, you can expand the existing persistent volume claims (PVCs). To expand a PVC, you must update the storage field in the PVC. Prerequisites Dynamic provisioning is used. The StorageClass object associated with the PVC has the allowVolumeExpansion field set to true . Procedure Log in to the OpenShift CLI ( oc ). Update the value of the spec.resources.requests.storage field to a value that is greater than the current value by running the following command: USD oc patch <pvc_name> -n <application_namespace> -p \ 1 '{ "spec": { "resources": { "requests": { "storage": "<desired_size>" }}}} --type=merge' 2 1 Replace <pvc_name> with the name of the PVC that you want to expand. 2 Replace <desired_size> with the new size to expand the PVC. Verification To verify that resizing is completed, run the following command: USD oc get pvc <pvc_name> -n <application_namespace> -o=jsonpath={.status.capacity.storage} LVM Storage adds the Resizing condition to the PVC during expansion. It deletes the Resizing condition after the PVC expansion. Additional resources Ways to scale up the storage of clusters Enabling volume expansion support 4.12.4.8. Deleting a persistent volume claim You can delete a persistent volume claim (PVC) by using the OpenShift CLI ( oc ). Prerequisites You have access to OpenShift Container Platform as a user with cluster-admin permissions. Procedure Log in to the OpenShift CLI ( oc ). Delete the PVC by running the following command: USD oc delete pvc <pvc_name> -n <namespace> Verification To verify that the PVC is deleted, run the following command: USD oc get pvc -n <namespace> The deleted PVC must not be present in the output of this command. 4.12.4.9. About volume snapshots You can create snapshots of persistent volume claims (PVCs) that are provisioned by LVM Storage. You can perform the following actions using the volume snapshots: Back up your application data. Important Volume snapshots are located on the same devices as the original data. To use the volume snapshots as backups, you must move the snapshots to a secure location. You can use OpenShift API for Data Protection (OADP) backup and restore solutions. For information about OADP, see "OADP features". Revert to a state at which the volume snapshot was taken. Note You can also create volume snapshots of the volume clones. 4.12.4.9.1. Limitations for creating volume snapshots in multi-node topology LVM Storage has the following limitations for creating volume snapshots in multi-node topology: Creating volume snapshots is based on the LVM thin pool capabilities. After creating a volume snapshot, the node must have additional storage space for further updating the original data source. You can create volume snapshots only on the node where you have deployed the original data source. Pods relying on the PVC that uses the snapshot data can be scheduled only on the node where you have deployed the original data source. Additional resources OADP features 4.12.4.9.2. Creating volume snapshots You can create volume snapshots based on the available capacity of the thin pool and the over-provisioning limits. To create a volume snapshot, you must create a VolumeSnapshotClass object. Prerequisites You have access to OpenShift Container Platform as a user with cluster-admin permissions. You ensured that the persistent volume claim (PVC) is in Bound state. This is required for a consistent snapshot. You stopped all the I/O to the PVC. Procedure Log in to the OpenShift CLI ( oc ). Create a VolumeSnapshot object: Example VolumeSnapshot object apiVersion: snapshot.storage.k8s.io/v1 kind: VolumeSnapshot metadata: name: lvm-block-1-snap 1 spec: source: persistentVolumeClaimName: lvm-block-1 2 volumeSnapshotClassName: lvms-vg1 3 1 Specify a name for the volume snapshot. 2 Specify the name of the source PVC. LVM Storage creates a snapshot of this PVC. 3 Set this field to the name of a volume snapshot class. Note To get the list of available volume snapshot classes, run the following command: USD oc get volumesnapshotclass Create the volume snapshot in the namespace where you created the source PVC by running the following command: USD oc create -f <file_name> -n <namespace> LVM Storage creates a read-only copy of the PVC as a volume snapshot. Verification To verify that the volume snapshot is created, run the following command: USD oc get volumesnapshot -n <namespace> Example output NAME READYTOUSE SOURCEPVC SOURCESNAPSHOTCONTENT RESTORESIZE SNAPSHOTCLASS SNAPSHOTCONTENT CREATIONTIME AGE lvm-block-1-snap true lvms-test-1 1Gi lvms-vg1 snapcontent-af409f97-55fc-40cf-975f-71e44fa2ca91 19s 19s The value of the READYTOUSE field for the volume snapshot that you created must be true . 4.12.4.9.3. Restoring volume snapshots To restore a volume snapshot, you must create a persistent volume claim (PVC) with the dataSource.name field set to the name of the volume snapshot. The restored PVC is independent of the volume snapshot and the source PVC. Prerequisites You have access to OpenShift Container Platform as a user with cluster-admin permissions. You have created a volume snapshot. Procedure Log in to the OpenShift CLI ( oc ). Create a PersistentVolumeClaim object with the configuration to restore the volume snapshot: Example PersistentVolumeClaim object to restore a volume snapshot kind: PersistentVolumeClaim apiVersion: v1 metadata: name: lvm-block-1-restore spec: accessModes: - ReadWriteOnce volumeMode: Block Resources: Requests: storage: 2Gi 1 storageClassName: lvms-vg1 2 dataSource: name: lvm-block-1-snap 3 kind: VolumeSnapshot apiGroup: snapshot.storage.k8s.io 1 Specify the storage size of the restored PVC. The storage size of the requested PVC must be greater than or equal to the stoage size of the volume snapshot that you want to restore. If a larger PVC is required, you can also resize the PVC after restoring the volume snapshot. 2 Set this field to the value of the storageClassName field in the source PVC of the volume snapshot that you want to restore. 3 Set this field to the name of the volume snapshot that you want to restore. Create the PVC in the namespace where you created the volume snapshot by running the following command: USD oc create -f <file_name> -n <namespace> Verification To verify that the volume snapshot is restored, run the following command: USD oc get pvc -n <namespace> Example output NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE lvm-block-1-restore Bound pvc-e90169a8-fd71-4eea-93b8-817155f60e47 1Gi RWO lvms-vg1 5s 4.12.4.9.4. Deleting volume snapshots You can delete the volume snapshots of the persistent volume claims (PVCs). Important When you delete a persistent volume claim (PVC), LVM Storage deletes only the PVC, but not the snapshots of the PVC. Prerequisites You have access to OpenShift Container Platform as a user with cluster-admin permissions. You have ensured that the volume snpashot that you want to delete is not in use. Procedure Log in to the OpenShift CLI ( oc ). Delete the volume snapshot by running the following command: USD oc delete volumesnapshot <volume_snapshot_name> -n <namespace> Verification To verify that the volume snapshot is deleted, run the following command: USD oc get volumesnapshot -n <namespace> The deleted volume snapshot must not be present in the output of this command. 4.12.4.10. About volume clones A volume clone is a duplicate of an existing persistent volume claim (PVC). You can create a volume clone to make a point-in-time copy of the data. 4.12.4.10.1. Limitations for creating volume clones in multi-node topology LVM Storage has the following limitations for creating volume clones in multi-node topology: Creating volume clones is based on the LVM thin pool capabilities. The node must have additional storage after creating a volume clone for further updating the original data source. You can create volume clones only on the node where you have deployed the original data source. Pods relying on the PVC that uses the clone data can be scheduled only on the node where you have deployed the original data source. 4.12.4.10.2. Creating volume clones To create a clone of a persistent volume claim (PVC), you must create a PersistentVolumeClaim object in the namespace where you created the source PVC. Important The cloned PVC has write access. Prerequisites You ensured that the source PVC is in Bound state. This is required for a consistent clone. Procedure Log in to the OpenShift CLI ( oc ). Create a PersistentVolumeClaim object: Example PersistentVolumeClaim object to create a volume clone kind: PersistentVolumeClaim apiVersion: v1 metadata: name: lvm-pvc-clone spec: accessModes: - ReadWriteOnce storageClassName: lvms-vg1 1 volumeMode: Filesystem 2 dataSource: kind: PersistentVolumeClaim name: lvm-pvc 3 resources: requests: storage: 1Gi 4 1 Set this field to the value of the storageClassName field in the source PVC. 2 Set this field to the volumeMode field in the source PVC. 3 Specify the name of the source PVC. 4 Specify the storage size for the cloned PVC. The storage size of the cloned PVC must be greater than or equal to the storage size of the source PVC. Create the PVC in the namespace where you created the source PVC by running the following command: USD oc create -f <file_name> -n <namespace> Verification To verify that the volume clone is created, run the following command: USD oc get pvc -n <namespace> Example output NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE lvm-block-1-clone Bound pvc-e90169a8-fd71-4eea-93b8-817155f60e47 1Gi RWO lvms-vg1 5s 4.12.4.10.3. Deleting volume clones You can delete volume clones. Important When you delete a persistent volume claim (PVC), LVM Storage deletes only the source persistent volume claim (PVC) but not the clones of the PVC. Prerequisites You have access to OpenShift Container Platform as a user with cluster-admin permissions. Procedure Log in to the OpenShift CLI ( oc ). Delete the cloned PVC by running the following command: # oc delete pvc <clone_pvc_name> -n <namespace> Verification To verify that the volume clone is deleted, run the following command: USD oc get pvc -n <namespace> The deleted volume clone must not be present in the output of this command. 4.12.4.11. Updating LVM Storage You can update LVM Storage to ensure compatibility with the OpenShift Container Platform version. Prerequisites You have updated your OpenShift Container Platform cluster. You have installed a version of LVM Storage. You have installed the OpenShift CLI ( oc ). You have access to the cluster using an account with cluster-admin permissions. Procedure Log in to the OpenShift CLI ( oc ). Update the Subscription custom resource (CR) that you created while installing LVM Storage by running the following command: USD oc patch subscription lvms-operator -n openshift-storage --type merge --patch '{"spec":{"channel":"<update_channel>"}}' 1 1 Replace <update_channel> with the version of LVM Storage that you want to install. For example, stable-4.17 . View the update events to check that the installation is complete by running the following command: USD oc get events -n openshift-storage Example output ... 8m13s Normal RequirementsUnknown clusterserviceversion/lvms-operator.v4.17 requirements not yet checked 8m11s Normal RequirementsNotMet clusterserviceversion/lvms-operator.v4.17 one or more requirements couldn't be found 7m50s Normal AllRequirementsMet clusterserviceversion/lvms-operator.v4.17 all requirements found, attempting install 7m50s Normal InstallSucceeded clusterserviceversion/lvms-operator.v4.17 waiting for install components to report healthy 7m49s Normal InstallWaiting clusterserviceversion/lvms-operator.v4.17 installing: waiting for deployment lvms-operator to become ready: deployment "lvms-operator" waiting for 1 outdated replica(s) to be terminated 7m39s Normal InstallSucceeded clusterserviceversion/lvms-operator.v4.17 install strategy completed with no errors ... Verification Verify the LVM Storage version by running the following command: USD oc get subscription lvms-operator -n openshift-storage -o jsonpath='{.status.installedCSV}' Example output lvms-operator.v4.17 4.12.4.12. Monitoring LVM Storage To enable cluster monitoring, you must add the following label in the namespace where you have installed LVM Storage: openshift.io/cluster-monitoring=true Important For information about enabling cluster monitoring in RHACM, see Observability and Adding custom metrics . 4.12.4.12.1. Metrics You can monitor LVM Storage by viewing the metrics. The following table describes the topolvm metrics: Table 4.9. topolvm metrics Alert Description topolvm_thinpool_data_percent Indicates the percentage of data space used in the LVM thinpool. topolvm_thinpool_metadata_percent Indicates the percentage of metadata space used in the LVM thinpool. topolvm_thinpool_size_bytes Indicates the size of the LVM thin pool in bytes. topolvm_volumegroup_available_bytes Indicates the available space in the LVM volume group in bytes. topolvm_volumegroup_size_bytes Indicates the size of the LVM volume group in bytes. topolvm_thinpool_overprovisioned_available Indicates the available over-provisioned size of the LVM thin pool in bytes. Note Metrics are updated every 10 minutes or when there is a change, such as a new logical volume creation, in the thin pool. 4.12.4.12.2. Alerts When the thin pool and volume group reach maximum storage capacity, further operations fail. This can lead to data loss. LVM Storage sends the following alerts when the usage of the thin pool and volume group exceeds a certain value: Table 4.10. LVM Storage alerts Alert Description VolumeGroupUsageAtThresholdNearFull This alert is triggered when both the volume group and thin pool usage exceeds 75% on nodes. Data deletion or volume group expansion is required. VolumeGroupUsageAtThresholdCritical This alert is triggered when both the volume group and thin pool usage exceeds 85% on nodes. In this case, the volume group is critically full. Data deletion or volume group expansion is required. ThinPoolDataUsageAtThresholdNearFull This alert is triggered when the thin pool data uusage in the volume group exceeds 75% on nodes. Data deletion or thin pool expansion is required. ThinPoolDataUsageAtThresholdCritical This alert is triggered when the thin pool data usage in the volume group exceeds 85% on nodes. Data deletion or thin pool expansion is required. ThinPoolMetaDataUsageAtThresholdNearFull This alert is triggered when the thin pool metadata usage in the volume group exceeds 75% on nodes. Data deletion or thin pool expansion is required. ThinPoolMetaDataUsageAtThresholdCritical This alert is triggered when the thin pool metadata usage in the volume group exceeds 85% on nodes. Data deletion or thin pool expansion is required. 4.12.4.13. Uninstalling LVM Storage by using the CLI You can uninstall LVM Storage by using the OpenShift CLI ( oc ). Prerequisites You have logged in to oc as a user with cluster-admin permissions. You deleted the persistent volume claims (PVCs), volume snapshots, and volume clones provisioned by LVM Storage. You have also deleted the applications that are using these resources. You deleted the LVMCluster custom resource (CR). Procedure Get the currentCSV value for the LVM Storage Operator by running the following command: USD oc get subscription.operators.coreos.com lvms-operator -n <namespace> -o yaml | grep currentCSV Example output currentCSV: lvms-operator.v4.15.3 Delete the subscription by running the following command: USD oc delete subscription.operators.coreos.com lvms-operator -n <namespace> Example output subscription.operators.coreos.com "lvms-operator" deleted Delete the CSV for the LVM Storage Operator in the target namespace by running the following command: USD oc delete clusterserviceversion <currentCSV> -n <namespace> 1 1 Replace <currentCSV> with the currentCSV value for the LVM Storage Operator. Example output clusterserviceversion.operators.coreos.com "lvms-operator.v4.15.3" deleted Verification To verify that the LVM Storage Operator is uninstalled, run the following command: USD oc get csv -n <namespace> If the LVM Storage Operator was successfully uninstalled, it does not appear in the output of this command. 4.12.4.14. Uninstalling LVM Storage by using the web console You can uninstall LVM Storage using the OpenShift Container Platform web console. Prerequisites You have access to OpenShift Container Platform as a user with cluster-admin permissions. You have deleted the persistent volume claims (PVCs), volume snapshots, and volume clones provisioned by LVM Storage. You have also deleted the applications that are using these resources. You have deleted the LVMCluster custom resource (CR). Procedure Log in to the OpenShift Container Platform web console. Click Operators Installed Operators . Click LVM Storage in the openshift-storage namespace. Click the Details tab. From the Actions menu, select Uninstall Operator . Optional: When prompted, select the Delete all operand instances for this operator checkbox to delete the operand instances for LVM Storage. Click Uninstall . 4.12.4.15. Uninstalling LVM Storage installed using RHACM To uninstall LVM Storage that you installed using RHACM, you must delete the RHACM Policy custom resource (CR) that you created for installing and configuring LVM Storage. Prerequisites You have access to the RHACM cluster as a user with cluster-admin permissions. You have deleted the persistent volume claims (PVCs), volume snapshots, and volume clones provisioned by LVM Storage. You have also deleted the applications that are using these resources. You have deleted the LVMCluster CR that you created using RHACM. Procedure Log in to the OpenShift CLI ( oc ). Delete the RHACM Policy CR that you created for installing and configuring LVM Storage by using the following command: USD oc delete -f <policy> -n <namespace> 1 1 Replace <policy> with the name of the Policy CR YAML file. Create a Policy CR YAML file with the configuration to uninstall LVM Storage: Example Policy CR to uninstall LVM Storage apiVersion: apps.open-cluster-management.io/v1 kind: PlacementRule metadata: name: placement-uninstall-lvms spec: clusterConditions: - status: "True" type: ManagedClusterConditionAvailable clusterSelector: matchExpressions: - key: mykey operator: In values: - myvalue --- apiVersion: policy.open-cluster-management.io/v1 kind: PlacementBinding metadata: name: binding-uninstall-lvms placementRef: apiGroup: apps.open-cluster-management.io kind: PlacementRule name: placement-uninstall-lvms subjects: - apiGroup: policy.open-cluster-management.io kind: Policy name: uninstall-lvms --- apiVersion: policy.open-cluster-management.io/v1 kind: Policy metadata: annotations: policy.open-cluster-management.io/categories: CM Configuration Management policy.open-cluster-management.io/controls: CM-2 Baseline Configuration policy.open-cluster-management.io/standards: NIST SP 800-53 name: uninstall-lvms spec: disabled: false policy-templates: - objectDefinition: apiVersion: policy.open-cluster-management.io/v1 kind: ConfigurationPolicy metadata: name: uninstall-lvms spec: object-templates: - complianceType: mustnothave objectDefinition: apiVersion: v1 kind: Namespace metadata: name: openshift-storage - complianceType: mustnothave objectDefinition: apiVersion: operators.coreos.com/v1 kind: OperatorGroup metadata: name: openshift-storage-operatorgroup namespace: openshift-storage spec: targetNamespaces: - openshift-storage - complianceType: mustnothave objectDefinition: apiVersion: operators.coreos.com/v1alpha1 kind: Subscription metadata: name: lvms-operator namespace: openshift-storage remediationAction: enforce severity: low - objectDefinition: apiVersion: policy.open-cluster-management.io/v1 kind: ConfigurationPolicy metadata: name: policy-remove-lvms-crds spec: object-templates: - complianceType: mustnothave objectDefinition: apiVersion: apiextensions.k8s.io/v1 kind: CustomResourceDefinition metadata: name: logicalvolumes.topolvm.io - complianceType: mustnothave objectDefinition: apiVersion: apiextensions.k8s.io/v1 kind: CustomResourceDefinition metadata: name: lvmclusters.lvm.topolvm.io - complianceType: mustnothave objectDefinition: apiVersion: apiextensions.k8s.io/v1 kind: CustomResourceDefinition metadata: name: lvmvolumegroupnodestatuses.lvm.topolvm.io - complianceType: mustnothave objectDefinition: apiVersion: apiextensions.k8s.io/v1 kind: CustomResourceDefinition metadata: name: lvmvolumegroups.lvm.topolvm.io remediationAction: enforce severity: high Create the Policy CR by running the following command: USD oc create -f <policy> -ns <namespace> 4.12.4.16. Downloading log files and diagnostic information using must-gather When LVM Storage is unable to automatically resolve a problem, use the must-gather tool to collect the log files and diagnostic information so that you or the Red Hat Support can review the problem and determine a solution. Procedure Run the must-gather command from the client connected to the LVM Storage cluster: USD oc adm must-gather --image=registry.redhat.io/lvms4/lvms-must-gather-rhel9:v4.17 --dest-dir=<directory_name> Additional resources About the must-gather tool 4.12.4.17. Troubleshooting persistent storage While configuring persistent storage using Logical Volume Manager (LVM) Storage, you can encounter several issues that require troubleshooting. 4.12.4.17.1. Investigating a PVC stuck in the Pending state A persistent volume claim (PVC) can get stuck in the Pending state for the following reasons: Insufficient computing resources. Network problems. Mismatched storage class or node selector. No available persistent volumes (PVs). The node with the PV is in the Not Ready state. Prerequisites You have installed the OpenShift CLI ( oc ). You have logged in to the OpenShift CLI ( oc ) as a user with cluster-admin permissions. Procedure Retrieve the list of PVCs by running the following command: USD oc get pvc Example output NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE lvms-test Pending lvms-vg1 11s Inspect the events associated with a PVC stuck in the Pending state by running the following command: USD oc describe pvc <pvc_name> 1 1 Replace <pvc_name> with the name of the PVC. For example, lvms-vg1 . Example output Type Reason Age From Message ---- ------ ---- ---- ------- Warning ProvisioningFailed 4s (x2 over 17s) persistentvolume-controller storageclass.storage.k8s.io "lvms-vg1" not found 4.12.4.17.2. Recovering from a missing storage class If you encounter the storage class not found error, check the LVMCluster custom resource (CR) and ensure that all the Logical Volume Manager (LVM) Storage pods are in the Running state. Prerequisites You have installed the OpenShift CLI ( oc ). You have logged in to the OpenShift CLI ( oc ) as a user with cluster-admin permissions. Procedure Verify that the LVMCluster CR is present by running the following command: USD oc get lvmcluster -n openshift-storage Example output NAME AGE my-lvmcluster 65m If the LVMCluster CR is not present, create an LVMCluster CR. For more information, see "Ways to create an LVMCluster custom resource". In the openshift-storage namespace, check that all the LVM Storage pods are in the Running state by running the following command: USD oc get pods -n openshift-storage Example output NAME READY STATUS RESTARTS AGE lvms-operator-7b9fb858cb-6nsml 3/3 Running 0 70m topolvm-controller-5dd9cf78b5-7wwr2 5/5 Running 0 66m topolvm-node-dr26h 4/4 Running 0 66m vg-manager-r6zdv 1/1 Running 0 66m The output of this command must contain a running instance of the following pods: lvms-operator vg-manager If the vg-manager pod is stuck while loading a configuration file, it is due to a failure to locate an available disk for LVM Storage to use. To retrieve the necessary information to troubleshoot this issue, review the logs of the vg-manager pod by running the following command: USD oc logs -l app.kubernetes.io/component=vg-manager -n openshift-storage Additional resources About the LVMCluster custom resource Ways to create an LVMCluster custom resource 4.12.4.17.3. Recovering from node failure A persistent volume claim (PVC) can be stuck in the Pending state due to a node failure in the cluster. To identify the failed node, you can examine the restart count of the topolvm-node pod. An increased restart count indicates potential problems with the underlying node, which might require further investigation and troubleshooting. Prerequisites You have installed the OpenShift CLI ( oc ). You have logged in to the OpenShift CLI ( oc ) as a user with cluster-admin permissions. Procedure Examine the restart count of the topolvm-node pod instances by running the following command: USD oc get pods -n openshift-storage Example output NAME READY STATUS RESTARTS AGE lvms-operator-7b9fb858cb-6nsml 3/3 Running 0 70m topolvm-controller-5dd9cf78b5-7wwr2 5/5 Running 0 66m topolvm-node-dr26h 4/4 Running 0 66m topolvm-node-54as8 4/4 Running 0 66m topolvm-node-78fft 4/4 Running 17 (8s ago) 66m vg-manager-r6zdv 1/1 Running 0 66m vg-manager-990ut 1/1 Running 0 66m vg-manager-an118 1/1 Running 0 66m steps If the PVC is stuck in the Pending state even after you have resolved any issues with the node, you must perform a forced clean-up. For more information, see "Performing a forced clean-up". Additional resources Performing a forced clean-up 4.12.4.17.4. Recovering from disk failure If you see a failure message while inspecting the events associated with the persistent volume claim (PVC), there can be a problem with the underlying volume or disk. Disk and volume provisioning issues result with a generic error message such as Failed to provision volume with storage class <storage_class_name> . The generic error message is followed by a specific volume failure error message. The following table describes the volume failure error messages: Table 4.11. Volume failure error messages Error message Description Failed to check volume existence Indicates a problem in verifying whether the volume already exists. Volume verification failure can be caused by network connectivity problems or other failures. Failed to bind volume Failure to bind a volume can happen if the persistent volume (PV) that is available does not match the requirements of the PVC. FailedMount or FailedAttachVolume This error indicates problems when trying to mount the volume to a node. If the disk has failed, this error can appear when a pod tries to use the PVC. FailedUnMount This error indicates problems when trying to unmount a volume from a node. If the disk has failed, this error can appear when a pod tries to use the PVC. Volume is already exclusively attached to one node and cannot be attached to another This error can appear with storage solutions that do not support ReadWriteMany access modes. Prerequisites You have installed the OpenShift CLI ( oc ). You have logged in to the OpenShift CLI ( oc ) as a user with cluster-admin permissions. Procedure Inspect the events associated with a PVC by running the following command: USD oc describe pvc <pvc_name> 1 1 Replace <pvc_name> with the name of the PVC. Establish a direct connection to the host where the problem is occurring. Resolve the disk issue. steps If the volume failure messages persist or recur even after you have resolved the issue with the disk, you must perform a forced clean-up. For more information, see "Performing a forced clean-up". Additional resources Performing a forced clean-up 4.12.4.17.5. Performing a forced clean-up If the disk or node-related problems persist even after you have completed the troubleshooting procedures, you must perform a forced clean-up. A forced clean-up is used to address persistent issues and ensure the proper functioning of Logical Volume Manager (LVM) Storage. Prerequisites You have installed the OpenShift CLI ( oc ). You have logged in to the OpenShift CLI ( oc ) as a user with cluster-admin permissions. You have deleted all the persistent volume claims (PVCs) that were created by using LVM Storage. You have stopped the pods that are using the PVCs that were created by using LVM Storage. Procedure Switch to the openshift-storage namespace by running the following command: USD oc project openshift-storage Check if the LogicalVolume custom resources (CRs) are present by running the following command: USD oc get logicalvolume If the LogicalVolume CRs are present, delete them by running the following command: USD oc delete logicalvolume <name> 1 1 Replace <name> with the name of the LogicalVolume CR. After deleting the LogicalVolume CRs, remove their finalizers by running the following command: USD oc patch logicalvolume <name> -p '{"metadata":{"finalizers":[]}}' --type=merge 1 1 Replace <name> with the name of the LogicalVolume CR. Check if the LVMVolumeGroup CRs are present by running the following command: USD oc get lvmvolumegroup If the LVMVolumeGroup CRs are present, delete them by running the following command: USD oc delete lvmvolumegroup <name> 1 1 Replace <name> with the name of the LVMVolumeGroup CR. After deleting the LVMVolumeGroup CRs, remove their finalizers by running the following command: USD oc patch lvmvolumegroup <name> -p '{"metadata":{"finalizers":[]}}' --type=merge 1 1 Replace <name> with the name of the LVMVolumeGroup CR. Delete any LVMVolumeGroupNodeStatus CRs by running the following command: USD oc delete lvmvolumegroupnodestatus --all Delete the LVMCluster CR by running the following command: USD oc delete lvmcluster --all After deleting the LVMCluster CR, remove its finalizer by running the following command: USD oc patch lvmcluster <name> -p '{"metadata":{"finalizers":[]}}' --type=merge 1 1 Replace <name> with the name of the LVMCluster CR.

Commands:
cat << EOF | oc create -f - apiVersion: storage.k8s.io/v1 kind: StorageClass metadata: name: <storage-class-name> 1 parameters: fsType: ext4 2 encrypted: "true" kmsKeyId: keyvalue 3 provisioner: ebs.csi.aws.com reclaimPolicy: Delete volumeBindingMode: WaitForFirstConsumer EOF
cat << EOF | oc create -f - apiVersion: v1 kind: PersistentVolumeClaim metadata: name: mypvc spec: accessModes: - ReadWriteOnce volumeMode: Filesystem storageClassName: <storage-class-name> resources: requests: storage: 1Gi EOF
cat << EOF | oc create -f - kind: Pod metadata: name: mypod spec: containers: - name: httpd image: quay.io/centos7/httpd-24-centos7 ports: - containerPort: 80 volumeMounts: - mountPath: /mnt/storage name: data volumes: - name: data persistentVolumeClaim: claimName: mypvc EOF
oc edit machineset <machine-set-name>
apiVersion: machine.openshift.io/v1beta1 kind: MachineSet spec: template: spec: metadata: labels: disk: ultrassd 1 providerSpec: value: ultraSSDCapability: Enabled 2
oc create -f <machine-set-name>.yaml
apiVersion: storage.k8s.io/v1 kind: StorageClass metadata: name: ultra-disk-sc 1 parameters: cachingMode: None diskIopsReadWrite: "2000" 2 diskMbpsReadWrite: "320" 3 kind: managed skuname: UltraSSD_LRS provisioner: disk.csi.azure.com 4 reclaimPolicy: Delete volumeBindingMode: WaitForFirstConsumer 5
apiVersion: v1 kind: PersistentVolumeClaim metadata: name: ultra-disk 1 spec: accessModes: - ReadWriteOnce storageClassName: ultra-disk-sc 2 resources: requests: storage: 4Gi 3
apiVersion: v1 kind: Pod metadata: name: nginx-ultra spec: nodeSelector: disk: ultrassd 1 containers: - name: nginx-ultra image: alpine:latest command: - "sleep" - "infinity" volumeMounts: - mountPath: "/mnt/azure" name: volume volumes: - name: volume persistentVolumeClaim: claimName: ultra-disk 2
oc get machines
oc debug node/<node-name> -- chroot /host lsblk
apiVersion: v1 kind: Pod metadata: name: ssd-benchmark1 spec: containers: - name: ssd-benchmark1 image: nginx ports: - containerPort: 80 name: "http-server" volumeMounts: - name: lun0p1 mountPath: "/tmp" volumes: - name: lun0p1 hostPath: path: /var/lib/lun0p1 type: DirectoryOrCreate nodeSelector: disktype: ultrassd
StorageAccountType UltraSSD_LRS can be used only when additionalCapabilities.ultraSSDEnabled is set.
oc -n <stuck_pod_namespace> describe pod <stuck_pod_name>
oc create secret generic <secret-name> --from-literal=azurestorageaccountname=<storage-account> \ 1 --from-literal=azurestorageaccountkey=<storage-account-key> 2
apiVersion: "v1" kind: "PersistentVolume" metadata: name: "pv0001" 1 spec: capacity: storage: "5Gi" 2 accessModes: - "ReadWriteOnce" storageClassName: azure-file-sc azureFile: secretName: <secret-name> 3 shareName: share-1 4 readOnly: false
apiVersion: "v1" kind: "PersistentVolumeClaim" metadata: name: "claim1" 1 spec: accessModes: - "ReadWriteOnce" resources: requests: storage: "5Gi" 2 storageClassName: azure-file-sc 3 volumeName: "pv0001" 4
apiVersion: v1 kind: Pod metadata: name: pod-name 1 spec: containers: volumeMounts: - mountPath: "/data" 2 name: azure-file-share volumes: - name: azure-file-share persistentVolumeClaim: claimName: claim1 3
apiVersion: "v1" kind: "PersistentVolume" metadata: name: "pv0001" 1 spec: capacity: storage: "5Gi" 2 accessModes: - "ReadWriteOnce" cinder: 3 fsType: "ext3" 4 volumeID: "f37a03aa-6212-4c62-a805-9ce139fab180" 5
oc create -f cinder-persistentvolume.yaml
oc create serviceaccount <service_account>
oc adm policy add-scc-to-user <new_scc> -z <service_account> -n <project>
apiVersion: v1 kind: ReplicationController metadata: name: frontend-1 spec: replicas: 1 1 selector: 2 name: frontend template: 3 metadata: labels: 4 name: frontend 5 spec: containers: - image: openshift/hello-openshift name: helloworld ports: - containerPort: 8080 protocol: TCP restartPolicy: Always serviceAccountName: <service_account> 6 securityContext: fsGroup: 7777 7
apiVersion: v1 kind: PersistentVolume metadata: name: pv0001 spec: capacity: storage: 1Gi accessModes: - ReadWriteOnce fc: wwids: [scsi-3600508b400105e210000900000490000] 1 targetWWNs: ['500a0981891b8dc5', '500a0981991b8dc5'] 2 lun: 2 3 fsType: ext4
{ "fooServer": "192.168.0.1:1234", 1 "fooVolumeName": "bar", "kubernetes.io/fsType": "ext4", 2 "kubernetes.io/readwrite": "ro", 3 "kubernetes.io/secret/<key name>": "<key value>", 4 "kubernetes.io/secret/<another key name>": "<another key value>", }
status: <Success/Failure/Not supported>
message: <Reason for success/failure>
apiVersion: v1 kind: PersistentVolume metadata: name: pv0001 1 spec: capacity: storage: 1Gi 2 accessModes: - ReadWriteOnce flexVolume: driver: openshift.com/foo 3 fsType: "ext4" 4 secretRef: foo-secret 5 readOnly: true 6 options: 7 fooServer: 192.168.0.1:1234 fooVolumeName: bar
"fsType":"<FS type>", "readwrite":"<rw>", "secret/key1":"<secret1>" "secret/keyN":"<secretN>"
apiVersion: v1 kind: PersistentVolume metadata: name: iscsi-pv spec: capacity: storage: 1Gi accessModes: - ReadWriteOnce iscsi: targetPortal: 10.16.154.81:3260 iqn: iqn.2014-12.example.server:storage.target00 lun: 0 fsType: 'ext4'
apiVersion: v1 kind: PersistentVolume metadata: name: iscsi-pv spec: capacity: storage: 1Gi accessModes: - ReadWriteOnce iscsi: targetPortal: 10.0.0.1:3260 iqn: iqn.2016-04.test.com:storage.target00 lun: 0 fsType: ext4 chapAuthDiscovery: true 1 chapAuthSession: true 2 secretRef: name: chap-secret 3
apiVersion: v1 kind: PersistentVolume metadata: name: iscsi-pv spec: capacity: storage: 1Gi accessModes: - ReadWriteOnce iscsi: targetPortal: 10.0.0.1:3260 portals: ['10.0.2.16:3260', '10.0.2.17:3260', '10.0.2.18:3260'] 1 iqn: iqn.2016-04.test.com:storage.target00 lun: 0 fsType: ext4 readOnly: false
apiVersion: v1 kind: PersistentVolume metadata: name: iscsi-pv spec: capacity: storage: 1Gi accessModes: - ReadWriteOnce iscsi: targetPortal: 10.0.0.1:3260 portals: ['10.0.2.16:3260', '10.0.2.17:3260', '10.0.2.18:3260'] iqn: iqn.2016-04.test.com:storage.target00 lun: 0 initiatorName: iqn.2016-04.test.com:custom.iqn 1 fsType: ext4 readOnly: false
apiVersion: v1 kind: PersistentVolume metadata: name: pv0001 1 spec: capacity: storage: 5Gi 2 accessModes: - ReadWriteOnce 3 nfs: 4 path: /tmp 5 server: 172.17.0.2 6 persistentVolumeReclaimPolicy: Retain 7
oc get pv
NAME LABELS CAPACITY ACCESSMODES STATUS CLAIM REASON AGE pv0001 <none> 5Gi RWO Available 31s
apiVersion: v1 kind: PersistentVolumeClaim metadata: name: nfs-claim1 spec: accessModes: - ReadWriteOnce 1 resources: requests: storage: 5Gi 2 volumeName: pv0001 storageClassName: ""
oc get pvc
NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE nfs-claim1 Bound pv0001 5Gi RWO 2m
ls -lZ /opt/nfs -d
drwxrws---. nfsnobody 5555 unconfined_u:object_r:usr_t:s0 /opt/nfs
id nfsnobody
uid=65534(nfsnobody) gid=65534(nfsnobody) groups=65534(nfsnobody)
spec: containers: - name: securityContext: 1 supplementalGroups: [5555] 2
spec: containers: 1 - name: securityContext: runAsUser: 65534 2
setsebool -P virt_use_nfs 1
/<example_fs> *(rw,root_squash)
iptables -I INPUT 1 -p tcp --dport 2049 -j ACCEPT
iptables -I INPUT 1 -p tcp --dport 2049 -j ACCEPT
iptables -I INPUT 1 -p tcp --dport 20048 -j ACCEPT
iptables -I INPUT 1 -p tcp --dport 111 -j ACCEPT
apiVersion: v1 kind: PersistentVolume metadata: name: nfs1 spec: capacity: storage: 1Mi accessModes: - ReadWriteMany nfs: server: 192.168.1.1 path: "/"
apiVersion: v1 kind: PersistentVolume metadata: name: nfs2 spec: capacity: storage: 1Mi accessModes: - ReadWriteMany nfs: server: 192.168.1.1 path: "/"
echo 'Y' > /sys/module/nfsd/parameters/nfs4_disable_idmapping
kind: PersistentVolumeClaim apiVersion: v1 metadata: name: pvc 1 spec: accessModes: - ReadWriteOnce 2 resources: requests: storage: 1Gi 3
oc create -f pvc.yaml
vmkfstools -c <size> /vmfs/volumes/<datastore-name>/volumes/<disk-name>.vmdk
shell vmware-vdiskmanager -c -t 0 -s <size> -a lsilogic <disk-name>.vmdk
apiVersion: v1 kind: PersistentVolume metadata: name: pv1 1 spec: capacity: storage: 1Gi 2 accessModes: - ReadWriteOnce persistentVolumeReclaimPolicy: Retain vsphereVolume: 3 volumePath: "[datastore1] volumes/myDisk" 4 fsType: ext4 5
oc create -f pv1.yaml
apiVersion: v1 kind: PersistentVolumeClaim metadata: name: pvc1 1 spec: accessModes: - ReadWriteOnce 2 resources: requests: storage: "1Gi" 3 volumeName: pv1 4
oc create -f pvc1.yaml
oc adm new-project openshift-local-storage
oc annotate namespace openshift-local-storage openshift.io/node-selector=''
oc annotate namespace openshift-local-storage workload.openshift.io/allowed='management'
apiVersion: operators.coreos.com/v1 kind: OperatorGroup metadata: name: local-operator-group namespace: openshift-local-storage spec: targetNamespaces: - openshift-local-storage --- apiVersion: operators.coreos.com/v1alpha1 kind: Subscription metadata: name: local-storage-operator namespace: openshift-local-storage spec: channel: stable installPlanApproval: Automatic 1 name: local-storage-operator source: redhat-operators sourceNamespace: openshift-marketplace
oc apply -f openshift-local-storage.yaml
oc -n openshift-local-storage get pods
NAME READY STATUS RESTARTS AGE local-storage-operator-746bf599c9-vlt5t 1/1 Running 0 19m
oc get csvs -n openshift-local-storage
NAME DISPLAY VERSION REPLACES PHASE local-storage-operator.4.2.26-202003230335 Local Storage 4.2.26-202003230335 Succeeded
apiVersion: "local.storage.openshift.io/v1" kind: "LocalVolume" metadata: name: "local-disks" namespace: "openshift-local-storage" 1 spec: nodeSelector: 2 nodeSelectorTerms: - matchExpressions: - key: kubernetes.io/hostname operator: In values: - ip-10-0-140-183 - ip-10-0-158-139 - ip-10-0-164-33 storageClassDevices: - storageClassName: "local-sc" 3 forceWipeDevicesAndDestroyAllData: false 4 volumeMode: Filesystem 5 fsType: xfs 6 devicePaths: 7 - /path/to/device 8
apiVersion: "local.storage.openshift.io/v1" kind: "LocalVolume" metadata: name: "local-disks" namespace: "openshift-local-storage" 1 spec: nodeSelector: 2 nodeSelectorTerms: - matchExpressions: - key: kubernetes.io/hostname operator: In values: - ip-10-0-136-143 - ip-10-0-140-255 - ip-10-0-144-180 storageClassDevices: - storageClassName: "local-sc" 3 forceWipeDevicesAndDestroyAllData: false 4 volumeMode: Block 5 devicePaths: 6 - /path/to/device 7
oc create -f <local-volume>.yaml
oc get all -n openshift-local-storage
NAME READY STATUS RESTARTS AGE pod/diskmaker-manager-9wzms 1/1 Running 0 5m43s pod/diskmaker-manager-jgvjp 1/1 Running 0 5m43s pod/diskmaker-manager-tbdsj 1/1 Running 0 5m43s pod/local-storage-operator-7db4bd9f79-t6k87 1/1 Running 0 14m NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE service/local-storage-operator-metrics ClusterIP 172.30.135.36 <none> 8383/TCP,8686/TCP 14m NAME DESIRED CURRENT READY UP-TO-DATE AVAILABLE NODE SELECTOR AGE daemonset.apps/diskmaker-manager 3 3 3 3 3 <none> 5m43s NAME READY UP-TO-DATE AVAILABLE AGE deployment.apps/local-storage-operator 1/1 1 1 14m NAME DESIRED CURRENT READY AGE replicaset.apps/local-storage-operator-7db4bd9f79 1 1 1 14m
oc get pv
NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE local-pv-1cec77cf 100Gi RWO Delete Available local-sc 88m local-pv-2ef7cd2a 100Gi RWO Delete Available local-sc 82m local-pv-3fa1c73 100Gi RWO Delete Available local-sc 48m
apiVersion: v1 kind: PersistentVolume metadata: name: example-pv-filesystem spec: capacity: storage: 100Gi volumeMode: Filesystem 1 accessModes: - ReadWriteOnce persistentVolumeReclaimPolicy: Delete storageClassName: local-sc 2 local: path: /dev/xvdf 3 nodeAffinity: required: nodeSelectorTerms: - matchExpressions: - key: kubernetes.io/hostname operator: In values: - example-node
apiVersion: v1 kind: PersistentVolume metadata: name: example-pv-block spec: capacity: storage: 100Gi volumeMode: Block 1 accessModes: - ReadWriteOnce persistentVolumeReclaimPolicy: Delete storageClassName: local-sc 2 local: path: /dev/xvdf 3 nodeAffinity: required: nodeSelectorTerms: - matchExpressions: - key: kubernetes.io/hostname operator: In values: - example-node
oc create -f <example-pv>.yaml
oc get pv
NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE example-pv-filesystem 100Gi RWO Delete Available local-sc 3m47s example-pv1 1Gi RWO Delete Bound local-storage/pvc1 local-sc 12h example-pv2 1Gi RWO Delete Bound local-storage/pvc2 local-sc 12h example-pv3 1Gi RWO Delete Bound local-storage/pvc3 local-sc 12h
kind: PersistentVolumeClaim apiVersion: v1 metadata: name: local-pvc-name 1 spec: accessModes: - ReadWriteOnce volumeMode: Filesystem 2 resources: requests: storage: 100Gi 3 storageClassName: local-sc 4
oc create -f <local-pvc>.yaml
apiVersion: v1 kind: Pod spec: containers: volumeMounts: - name: local-disks 1 mountPath: /data 2 volumes: - name: local-disks persistentVolumeClaim: claimName: local-pvc-name 3
oc create -f <local-pod>.yaml
apiVersion: local.storage.openshift.io/v1alpha1 kind: LocalVolumeSet metadata: name: example-autodetect spec: nodeSelector: nodeSelectorTerms: - matchExpressions: - key: kubernetes.io/hostname operator: In values: - worker-0 - worker-1 storageClassName: local-sc 1 volumeMode: Filesystem fsType: ext4 maxDeviceCount: 10 deviceInclusionSpec: deviceTypes: 2 - disk - part deviceMechanicalProperties: - NonRotational minSize: 10G maxSize: 100G models: - SAMSUNG - Crucial_CT525MX3 vendors: - ATA - ST2000LM
oc apply -f local-volume-set.yaml
oc get pv
NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE local-pv-1cec77cf 100Gi RWO Delete Available local-sc 88m local-pv-2ef7cd2a 100Gi RWO Delete Available local-sc 82m local-pv-3fa1c73 100Gi RWO Delete Available local-sc 48m
apiVersion: "local.storage.openshift.io/v1" kind: "LocalVolume" metadata: name: "local-disks" namespace: "openshift-local-storage" spec: tolerations: - key: localstorage 1 operator: Equal 2 value: "localstorage" 3 storageClassDevices: - storageClassName: "local-sc" volumeMode: Block 4 devicePaths: 5 - /dev/xvdg
spec: tolerations: - key: node-role.kubernetes.io/master operator: Exists
oc edit localvolume <name> -n openshift-local-storage
oc delete pv <pv-name>
oc debug node/<node-name> -- chroot /host rm -rf /mnt/local-storage/<sc-name> 1
oc delete localvolume --all --all-namespaces oc delete localvolumeset --all --all-namespaces oc delete localvolumediscovery --all --all-namespaces
oc delete pv <pv-name>
oc delete project openshift-local-storage
apiVersion: v1 kind: Pod metadata: name: test-host-mount spec: containers: - image: registry.access.redhat.com/ubi9/ubi name: test-container command: ['sh', '-c', 'sleep 3600'] volumeMounts: - mountPath: /host name: host-slash volumes: - name: host-slash hostPath: path: / type: ''
apiVersion: v1 kind: PersistentVolume metadata: name: task-pv-volume 1 labels: type: local spec: storageClassName: manual 2 capacity: storage: 5Gi accessModes: - ReadWriteOnce 3 persistentVolumeReclaimPolicy: Retain hostPath: path: "/mnt/data" 4
oc create -f pv.yaml
apiVersion: v1 kind: PersistentVolumeClaim metadata: name: task-pvc-volume spec: accessModes: - ReadWriteOnce resources: requests: storage: 1Gi storageClassName: manual
oc create -f pvc.yaml
apiVersion: v1 kind: Pod metadata: name: pod-name 1 spec: containers: securityContext: privileged: true 2 volumeMounts: - mountPath: /data 3 name: hostpath-privileged securityContext: {} volumes: - name: hostpath-privileged persistentVolumeClaim: claimName: task-pvc-volume 4
apiVersion: v1 kind: Namespace metadata: labels: openshift.io/cluster-monitoring: "true" pod-security.kubernetes.io/enforce: privileged pod-security.kubernetes.io/audit: privileged pod-security.kubernetes.io/warn: privileged name: openshift-storage
oc create -f <file_name>
apiVersion: operators.coreos.com/v1 kind: OperatorGroup metadata: name: openshift-storage-operatorgroup namespace: openshift-storage spec: targetNamespaces: - openshift-storage
oc create -f <file_name>
apiVersion: operators.coreos.com/v1alpha1 kind: Subscription metadata: name: lvms namespace: openshift-storage spec: installPlanApproval: Automatic name: lvms-operator source: redhat-operators sourceNamespace: openshift-marketplace
oc create -f <file_name>
oc get csv -n openshift-storage -o custom-columns=Name:.metadata.name,Phase:.status.phase
Name Phase 4.13.0-202301261535 Succeeded
kind: ImageSetConfiguration apiVersion: mirror.openshift.io/v1alpha2 archiveSize: 4 1 storageConfig: 2 registry: imageURL: example.com/mirror/oc-mirror-metadata 3 skipTLS: false mirror: platform: channels: - name: stable-4.17 4 type: ocp graph: true 5 operators: - catalog: registry.redhat.io/redhat/redhat-operator-index:v4.17 6 packages: - name: lvms-operator 7 channels: - name: stable 8 additionalImages: - name: registry.redhat.io/ubi9/ubi:latest 9 helm: {}
oc create ns <namespace>
apiVersion: apps.open-cluster-management.io/v1 kind: PlacementRule metadata: name: placement-install-lvms spec: clusterConditions: - status: "True" type: ManagedClusterConditionAvailable clusterSelector: 1 matchExpressions: - key: mykey operator: In values: - myvalue --- apiVersion: policy.open-cluster-management.io/v1 kind: PlacementBinding metadata: name: binding-install-lvms placementRef: apiGroup: apps.open-cluster-management.io kind: PlacementRule name: placement-install-lvms subjects: - apiGroup: policy.open-cluster-management.io kind: Policy name: install-lvms --- apiVersion: policy.open-cluster-management.io/v1 kind: Policy metadata: annotations: policy.open-cluster-management.io/categories: CM Configuration Management policy.open-cluster-management.io/controls: CM-2 Baseline Configuration policy.open-cluster-management.io/standards: NIST SP 800-53 name: install-lvms spec: disabled: false remediationAction: enforce policy-templates: - objectDefinition: apiVersion: policy.open-cluster-management.io/v1 kind: ConfigurationPolicy metadata: name: install-lvms spec: object-templates: - complianceType: musthave objectDefinition: 2 apiVersion: v1 kind: Namespace metadata: labels: openshift.io/cluster-monitoring: "true" pod-security.kubernetes.io/enforce: privileged pod-security.kubernetes.io/audit: privileged pod-security.kubernetes.io/warn: privileged name: openshift-storage - complianceType: musthave objectDefinition: 3 apiVersion: operators.coreos.com/v1 kind: OperatorGroup metadata: name: openshift-storage-operatorgroup namespace: openshift-storage spec: targetNamespaces: - openshift-storage - complianceType: musthave objectDefinition: 4 apiVersion: operators.coreos.com/v1alpha1 kind: Subscription metadata: name: lvms namespace: openshift-storage spec: installPlanApproval: Automatic name: lvms-operator source: redhat-operators sourceNamespace: openshift-marketplace remediationAction: enforce severity: low
oc create -f <file_name> -n <namespace>
apiVersion: lvm.topolvm.io/v1alpha1 kind: LVMCluster metadata: name: my-lvmcluster spec: tolerations: - effect: NoSchedule key: xyz operator: Equal value: "true" storage: deviceClasses: - name: vg1 fstype: ext4 1 default: true nodeSelector: 2 nodeSelectorTerms: - matchExpressions: - key: mykey operator: In values: - ssd deviceSelector: 3 paths: - /dev/disk/by-path/pci-0000:87:00.0-nvme-1 - /dev/disk/by-path/pci-0000:88:00.0-nvme-1 optionalPaths: - /dev/disk/by-path/pci-0000:89:00.0-nvme-1 - /dev/disk/by-path/pci-0000:90:00.0-nvme-1 forceWipeDevicesAndDestroyAllData: true thinPoolConfig: name: thin-pool-1 sizePercent: 90 4 overprovisionRatio: 10 chunkSize: 128Ki 5 chunkSizeCalculationPolicy: Static 6
lsblk --paths --json -o NAME,ROTA,TYPE,SIZE,MODEL,VENDOR,RO,STATE,KNAME,SERIAL,PARTLABEL,FSTYPE
pvs <device-name> 1
cat /proc/1/mountinfo | grep <device-name> 1
apiVersion: lvm.topolvm.io/v1alpha1 kind: LVMCluster metadata: name: my-lvmcluster spec: storage: deviceClasses: - name: vg1 1 fstype: ext4 2 default: true deviceSelector: 3 forceWipeDevicesAndDestroyAllData: false 4 thinPoolConfig: 5 nodeSelector: 6
pvs -S vgname=<vg_name> 1
apiVersion: lvm.topolvm.io/v1alpha1 kind: LVMCluster metadata: name: my-lvmcluster spec: storage: deviceClasses: 1 nodeSelector: 2 deviceSelector: 3 thinPoolConfig: 4
oc create -f <file_name>
lvmcluster/lvmcluster created
oc get lvmclusters.lvm.topolvm.io -o jsonpath='{.items[*].status}' -n <namespace>
{"deviceClassStatuses": 1 [ { "name": "vg1", "nodeStatus": [ 2 { "devices": [ 3 "/dev/nvme0n1", "/dev/nvme1n1", "/dev/nvme2n1" ], "node": "kube-node", 4 "status": "Ready" 5 } ] } ] "state":"Ready"} 6
status: deviceClassStatuses: - name: vg1 nodeStatus: - node: my-node-1.example.com reason: no available devices found for volume group status: Failed state: Failed
oc get storageclass
NAME PROVISIONER RECLAIMPOLICY VOLUMEBINDINGMODE ALLOWVOLUMEEXPANSION AGE lvms-vg1 topolvm.io Delete WaitForFirstConsumer true 31m
oc get volumesnapshotclass
NAME DRIVER DELETIONPOLICY AGE lvms-vg1 topolvm.io Delete 24h
apiVersion: policy.open-cluster-management.io/v1 kind: ConfigurationPolicy metadata: name: lvms spec: object-templates: - complianceType: musthave objectDefinition: apiVersion: lvm.topolvm.io/v1alpha1 kind: LVMCluster metadata: name: my-lvmcluster namespace: openshift-storage spec: storage: deviceClasses: 1 deviceSelector: 2 thinPoolConfig: 3 nodeSelector: 4 remediationAction: enforce severity: low
oc create -f <file_name> -n <cluster_namespace> 1
oc delete lvmcluster <lvmclustername> -n openshift-storage
oc get lvmcluster -n <namespace>
No resources found in openshift-storage namespace.
oc delete -f <file_name> -n <cluster_namespace> 1
apiVersion: policy.open-cluster-management.io/v1 kind: Policy metadata: name: policy-lvmcluster-delete annotations: policy.open-cluster-management.io/standards: NIST SP 800-53 policy.open-cluster-management.io/categories: CM Configuration Management policy.open-cluster-management.io/controls: CM-2 Baseline Configuration spec: remediationAction: enforce disabled: false policy-templates: - objectDefinition: apiVersion: policy.open-cluster-management.io/v1 kind: ConfigurationPolicy metadata: name: policy-lvmcluster-removal spec: remediationAction: enforce 1 severity: low object-templates: - complianceType: mustnothave objectDefinition: kind: LVMCluster apiVersion: lvm.topolvm.io/v1alpha1 metadata: name: my-lvmcluster namespace: openshift-storage 2 --- apiVersion: policy.open-cluster-management.io/v1 kind: PlacementBinding metadata: name: binding-policy-lvmcluster-delete placementRef: apiGroup: apps.open-cluster-management.io kind: PlacementRule name: placement-policy-lvmcluster-delete subjects: - apiGroup: policy.open-cluster-management.io kind: Policy name: policy-lvmcluster-delete --- apiVersion: apps.open-cluster-management.io/v1 kind: PlacementRule metadata: name: placement-policy-lvmcluster-delete spec: clusterConditions: - status: "True" type: ManagedClusterConditionAvailable clusterSelector: 3 matchExpressions: - key: mykey operator: In values: - myvalue
oc create -f <file_name> -n <namespace>
apiVersion: policy.open-cluster-management.io/v1 kind: Policy metadata: name: policy-lvmcluster-inform annotations: policy.open-cluster-management.io/standards: NIST SP 800-53 policy.open-cluster-management.io/categories: CM Configuration Management policy.open-cluster-management.io/controls: CM-2 Baseline Configuration spec: remediationAction: inform disabled: false policy-templates: - objectDefinition: apiVersion: policy.open-cluster-management.io/v1 kind: ConfigurationPolicy metadata: name: policy-lvmcluster-removal-inform spec: remediationAction: inform 1 severity: low object-templates: - complianceType: mustnothave objectDefinition: kind: LVMCluster apiVersion: lvm.topolvm.io/v1alpha1 metadata: name: my-lvmcluster namespace: openshift-storage 2 --- apiVersion: policy.open-cluster-management.io/v1 kind: PlacementBinding metadata: name: binding-policy-lvmcluster-check placementRef: apiGroup: apps.open-cluster-management.io kind: PlacementRule name: placement-policy-lvmcluster-check subjects: - apiGroup: policy.open-cluster-management.io kind: Policy name: policy-lvmcluster-inform --- apiVersion: apps.open-cluster-management.io/v1 kind: PlacementRule metadata: name: placement-policy-lvmcluster-check spec: clusterConditions: - status: "True" type: ManagedClusterConditionAvailable clusterSelector: matchExpressions: - key: mykey operator: In values: - myvalue
oc create -f <file_name> -n <namespace>
oc get policy -n <namespace>
NAME REMEDIATION ACTION COMPLIANCE STATE AGE policy-lvmcluster-delete enforce Compliant 15m policy-lvmcluster-inform inform Compliant 15m
apiVersion: v1 kind: PersistentVolumeClaim metadata: name: lvm-block-1 1 namespace: default spec: accessModes: - ReadWriteOnce volumeMode: Block 2 resources: requests: storage: 10Gi 3 limits: storage: 20Gi 4 storageClassName: lvms-vg1 5
oc create -f <file_name> -n <application_namespace>
oc get pvc -n <namespace>
NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE lvm-block-1 Bound pvc-e90169a8-fd71-4eea-93b8-817155f60e47 1Gi RWO lvms-vg1 5s
oc edit <lvmcluster_file_name> -n <namespace>
apiVersion: lvm.topolvm.io/v1alpha1 kind: LVMCluster metadata: name: my-lvmcluster spec: storage: deviceClasses: deviceSelector: 1 paths: 2 - /dev/disk/by-path/pci-0000:87:00.0-nvme-1 - /dev/disk/by-path/pci-0000:88:00.0-nvme-1 optionalPaths: 3 - /dev/disk/by-path/pci-0000:89:00.0-nvme-1 - /dev/disk/by-path/pci-0000:90:00.0-nvme-1
apiVersion: lvm.topolvm.io/v1alpha1 kind: LVMCluster metadata: name: my-lvmcluster spec: storage: deviceClasses: deviceSelector: 1 paths: 2 - /dev/disk/by-path/pci-0000:87:00.0-nvme-1 - /dev/disk/by-path/pci-0000:88:00.0-nvme-1 optionalPaths: 3 - /dev/disk/by-path/pci-0000:89:00.0-nvme-1 - /dev/disk/by-path/pci-0000:90:00.0-nvme-1
oc edit -f <file_name> -ns <namespace> 1
apiVersion: policy.open-cluster-management.io/v1 kind: ConfigurationPolicy metadata: name: lvms spec: object-templates: - complianceType: musthave objectDefinition: apiVersion: lvm.topolvm.io/v1alpha1 kind: LVMCluster metadata: name: my-lvmcluster namespace: openshift-storage spec: storage: deviceClasses: deviceSelector: 1 paths: 2 - /dev/disk/by-path/pci-0000:87:00.0-nvme-1 optionalPaths: 3 - /dev/disk/by-path/pci-0000:89:00.0-nvme-1
oc patch <pvc_name> -n <application_namespace> -p \ 1 '{ "spec": { "resources": { "requests": { "storage": "<desired_size>" }}}} --type=merge' 2
oc get pvc <pvc_name> -n <application_namespace> -o=jsonpath={.status.capacity.storage}
oc delete pvc <pvc_name> -n <namespace>
oc get pvc -n <namespace>
apiVersion: snapshot.storage.k8s.io/v1 kind: VolumeSnapshot metadata: name: lvm-block-1-snap 1 spec: source: persistentVolumeClaimName: lvm-block-1 2 volumeSnapshotClassName: lvms-vg1 3
oc get volumesnapshotclass
oc create -f <file_name> -n <namespace>
oc get volumesnapshot -n <namespace>
NAME READYTOUSE SOURCEPVC SOURCESNAPSHOTCONTENT RESTORESIZE SNAPSHOTCLASS SNAPSHOTCONTENT CREATIONTIME AGE lvm-block-1-snap true lvms-test-1 1Gi lvms-vg1 snapcontent-af409f97-55fc-40cf-975f-71e44fa2ca91 19s 19s
kind: PersistentVolumeClaim apiVersion: v1 metadata: name: lvm-block-1-restore spec: accessModes: - ReadWriteOnce volumeMode: Block Resources: Requests: storage: 2Gi 1 storageClassName: lvms-vg1 2 dataSource: name: lvm-block-1-snap 3 kind: VolumeSnapshot apiGroup: snapshot.storage.k8s.io
oc create -f <file_name> -n <namespace>
oc get pvc -n <namespace>
NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE lvm-block-1-restore Bound pvc-e90169a8-fd71-4eea-93b8-817155f60e47 1Gi RWO lvms-vg1 5s
oc delete volumesnapshot <volume_snapshot_name> -n <namespace>
oc get volumesnapshot -n <namespace>
kind: PersistentVolumeClaim apiVersion: v1 metadata: name: lvm-pvc-clone spec: accessModes: - ReadWriteOnce storageClassName: lvms-vg1 1 volumeMode: Filesystem 2 dataSource: kind: PersistentVolumeClaim name: lvm-pvc 3 resources: requests: storage: 1Gi 4
oc create -f <file_name> -n <namespace>
oc get pvc -n <namespace>
NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE lvm-block-1-clone Bound pvc-e90169a8-fd71-4eea-93b8-817155f60e47 1Gi RWO lvms-vg1 5s
oc delete pvc <clone_pvc_name> -n <namespace>
oc get pvc -n <namespace>
oc patch subscription lvms-operator -n openshift-storage --type merge --patch '{"spec":{"channel":"<update_channel>"}}' 1
oc get events -n openshift-storage
8m13s Normal RequirementsUnknown clusterserviceversion/lvms-operator.v4.17 requirements not yet checked 8m11s Normal RequirementsNotMet clusterserviceversion/lvms-operator.v4.17 one or more requirements couldn't be found 7m50s Normal AllRequirementsMet clusterserviceversion/lvms-operator.v4.17 all requirements found, attempting install 7m50s Normal InstallSucceeded clusterserviceversion/lvms-operator.v4.17 waiting for install components to report healthy 7m49s Normal InstallWaiting clusterserviceversion/lvms-operator.v4.17 installing: waiting for deployment lvms-operator to become ready: deployment "lvms-operator" waiting for 1 outdated replica(s) to be terminated 7m39s Normal InstallSucceeded clusterserviceversion/lvms-operator.v4.17 install strategy completed with no errors
oc get subscription lvms-operator -n openshift-storage -o jsonpath='{.status.installedCSV}'
lvms-operator.v4.17
openshift.io/cluster-monitoring=true
oc get subscription.operators.coreos.com lvms-operator -n <namespace> -o yaml | grep currentCSV
currentCSV: lvms-operator.v4.15.3
oc delete subscription.operators.coreos.com lvms-operator -n <namespace>
subscription.operators.coreos.com "lvms-operator" deleted
oc delete clusterserviceversion <currentCSV> -n <namespace> 1
clusterserviceversion.operators.coreos.com "lvms-operator.v4.15.3" deleted
oc get csv -n <namespace>
oc delete -f <policy> -n <namespace> 1
apiVersion: apps.open-cluster-management.io/v1 kind: PlacementRule metadata: name: placement-uninstall-lvms spec: clusterConditions: - status: "True" type: ManagedClusterConditionAvailable clusterSelector: matchExpressions: - key: mykey operator: In values: - myvalue --- apiVersion: policy.open-cluster-management.io/v1 kind: PlacementBinding metadata: name: binding-uninstall-lvms placementRef: apiGroup: apps.open-cluster-management.io kind: PlacementRule name: placement-uninstall-lvms subjects: - apiGroup: policy.open-cluster-management.io kind: Policy name: uninstall-lvms --- apiVersion: policy.open-cluster-management.io/v1 kind: Policy metadata: annotations: policy.open-cluster-management.io/categories: CM Configuration Management policy.open-cluster-management.io/controls: CM-2 Baseline Configuration policy.open-cluster-management.io/standards: NIST SP 800-53 name: uninstall-lvms spec: disabled: false policy-templates: - objectDefinition: apiVersion: policy.open-cluster-management.io/v1 kind: ConfigurationPolicy metadata: name: uninstall-lvms spec: object-templates: - complianceType: mustnothave objectDefinition: apiVersion: v1 kind: Namespace metadata: name: openshift-storage - complianceType: mustnothave objectDefinition: apiVersion: operators.coreos.com/v1 kind: OperatorGroup metadata: name: openshift-storage-operatorgroup namespace: openshift-storage spec: targetNamespaces: - openshift-storage - complianceType: mustnothave objectDefinition: apiVersion: operators.coreos.com/v1alpha1 kind: Subscription metadata: name: lvms-operator namespace: openshift-storage remediationAction: enforce severity: low - objectDefinition: apiVersion: policy.open-cluster-management.io/v1 kind: ConfigurationPolicy metadata: name: policy-remove-lvms-crds spec: object-templates: - complianceType: mustnothave objectDefinition: apiVersion: apiextensions.k8s.io/v1 kind: CustomResourceDefinition metadata: name: logicalvolumes.topolvm.io - complianceType: mustnothave objectDefinition: apiVersion: apiextensions.k8s.io/v1 kind: CustomResourceDefinition metadata: name: lvmclusters.lvm.topolvm.io - complianceType: mustnothave objectDefinition: apiVersion: apiextensions.k8s.io/v1 kind: CustomResourceDefinition metadata: name: lvmvolumegroupnodestatuses.lvm.topolvm.io - complianceType: mustnothave objectDefinition: apiVersion: apiextensions.k8s.io/v1 kind: CustomResourceDefinition metadata: name: lvmvolumegroups.lvm.topolvm.io remediationAction: enforce severity: high
oc create -f <policy> -ns <namespace>
oc adm must-gather --image=registry.redhat.io/lvms4/lvms-must-gather-rhel9:v4.17 --dest-dir=<directory_name>
oc get pvc
NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE lvms-test Pending lvms-vg1 11s
oc describe pvc <pvc_name> 1
Type Reason Age From Message ---- ------ ---- ---- ------- Warning ProvisioningFailed 4s (x2 over 17s) persistentvolume-controller storageclass.storage.k8s.io "lvms-vg1" not found
oc get lvmcluster -n openshift-storage
NAME AGE my-lvmcluster 65m
oc get pods -n openshift-storage
NAME READY STATUS RESTARTS AGE lvms-operator-7b9fb858cb-6nsml 3/3 Running 0 70m topolvm-controller-5dd9cf78b5-7wwr2 5/5 Running 0 66m topolvm-node-dr26h 4/4 Running 0 66m vg-manager-r6zdv 1/1 Running 0 66m
oc logs -l app.kubernetes.io/component=vg-manager -n openshift-storage
oc get pods -n openshift-storage
NAME READY STATUS RESTARTS AGE lvms-operator-7b9fb858cb-6nsml 3/3 Running 0 70m topolvm-controller-5dd9cf78b5-7wwr2 5/5 Running 0 66m topolvm-node-dr26h 4/4 Running 0 66m topolvm-node-54as8 4/4 Running 0 66m topolvm-node-78fft 4/4 Running 17 (8s ago) 66m vg-manager-r6zdv 1/1 Running 0 66m vg-manager-990ut 1/1 Running 0 66m vg-manager-an118 1/1 Running 0 66m
oc describe pvc <pvc_name> 1
oc project openshift-storage
oc get logicalvolume
oc delete logicalvolume <name> 1
oc patch logicalvolume <name> -p '{"metadata":{"finalizers":[]}}' --type=merge 1
oc get lvmvolumegroup
oc delete lvmvolumegroup <name> 1
oc patch lvmvolumegroup <name> -p '{"metadata":{"finalizers":[]}}' --type=merge 1
oc delete lvmvolumegroupnodestatus --all
oc delete lvmcluster --all
oc patch lvmcluster <name> -p '{"metadata":{"finalizers":[]}}' --type=merge 1