Project: Rook (Runtime / Cloud Native Storage)
File: ceph-csi-drivers.md

title: Ceph CSI Drivers There are three CSI drivers integrated with Rook that are used in different scenarios: RBD: This block storage driver is optimized for RWO pod access where only one pod may access the storage. . CephFS: This file storage driver allows for RWX with one or more pods accessing the same storage. . NFS (experimental): This file storage driver allows creating NFS exports that can be mounted on pods, or directly via an NFS client from inside or outside the Kubernetes cluster. The Ceph Filesystem (CephFS) and RADOS Block Device (RBD) drivers are enabled automatically by the Rook operator. The NFS driver is disabled by default. All drivers will be started in the same namespace as the operator when the first CephCluster CR is created. The two most recent Ceph CSI version are supported with Rook. Refer to ceph csi for more information. The RBD and CephFS drivers support the creation of static PVs and static PVCs from an existing RBD image or CephFS volume/subvolume. Refer to the documentation for more information. If you've deployed the Rook operator in a namespace other than `rook-ceph`, change the prefix in the provisioner to match the namespace you used. For example, if the Rook operator is running in the namespace `my-namespace` the provisioner value should be `my-namespace.rbd.csi.ceph.com`. The same provisioner name must be set in both the storageclass and snapshotclass. To find the provisioner name in the example storageclasses and volumesnapshotclass, search for: `# csi-provisioner-name` To use a custom prefix for the CSI drivers instead of the namespace prefix, set the `CSIDRIVERNAME_PREFIX` environment variable in the operator configmap. For instance, to use the prefix `my-prefix` for the CSI drivers, set the following in the operator configmap: ```console kubectl patch cm rook-ceph-operator-config -n rook-ceph -p $'data:\n "CSIDRIVERNAME_PREFIX": "my-prefix"' ``` Once the configmap is updated, the CSI drivers will be deployed with the `my-prefix` prefix. The same prefix must be set in both the storageclass and snapshotclass. For example, to use the prefix `my-prefix` for the CSI drivers, update the provisioner in the storageclass: ```yaml apiVersion: storage.k8s.io/v1 kind: StorageClass metadata: name: rook-ceph-block-sc provisioner: my-prefix.rbd.csi.ceph.com ... ``` The same prefix must be set in the volumesnapshotclass as well: ```yaml apiVersion: snapshot.storage.k8s.io/v1 kind: VolumeSnapshotClass metadata: name: rook-ceph-block-vsc driver: my-prefix.rbd.csi.ceph.com ... ``` When the prefix is set, the driver names will be: RBD: `my-prefix.rbd.csi.ceph.com` CephFS: `my-prefix.cephfs.csi.ceph.com` NFS: `my-prefix.nfs.csi.ceph.com` !!! note Please be careful when setting the `CSIDRIVERNAME_PREFIX` environment

It should be done only in fresh deployments because changing the prefix in an existing cluster will result in unexpected behavior. To find the provisioner name in the example storageclasses and volumesnapshotclass, search for: `# csi-provisioner-name` All CSI pods are deployed with a sidecar container that provides a Prometheus metric for tracking whether the CSI plugin is alive and running. Check the to see how to integrate CSI liveness and GRPC metrics into Ceph monitoring. To expand the PVC the controlling StorageClass must have `allowVolumeExpansion` set to `true`. `csi.storage.k8s.io/controller-expand-secret-name` and `csi.storage.k8s.io/controller-expand-secret-namespace` values set in the storageclass. Now expand the PVC by editing the PVC's `pvc.spec.resource.requests.storage` to a higher values than the current size. Once the PVC is expanded on the back end and the new size is reflected on the application mountpoint, the status capacity `pvc.status.capacity.storage` of the PVC will be updated to the new size. To support RBD Mirroring, the will be started in the RBD provisioner pod. CSI-Addons support the `VolumeReplication` operation. The volume replication controller provides common and reusable APIs for storage disaster recovery. It is based on the specification. It follows the controller pattern and provides extended APIs for storage disaster recovery. The extended APIs are provided via Custom Resource Definitions (CRDs). To enable the CSIAddons sidecar and deploy the controller, follow the steps The generic ephemeral volume feature adds support for specifying PVCs in the `volumes` field to create a Volume as part of the pod spec. This feature requires the `GenericEphemeralVolume` feature gate to be enabled. For example: ```yaml kind: Pod apiVersion: v1 ... volumes: name: mypvc ephemeral: volumeClaimTemplate: spec: accessModes: ["ReadWriteOnce"] storageClassName: "rook-ceph-block" resources: requests: storage: 1Gi ``` A volume claim template is defined inside the pod spec, and defines a volume to be provisioned and used by the pod within its lifecycle. Volumes are provisioned when a pod is spawned and destroyed when the pod is deleted. Refer to the for more info. See example manifests for an and a . The CSI-Addons Controller handles requests from users. Users create a CR that the controller inspects and forwards to one or more CSI-Addons sidecars for execution. Deploy the controller by running the following commands: ```console kubectl create -f https://raw.githubusercontent.com/csi-addons/kubernetes-csi-addons/v0.8.0/deploy/controller/crds.yaml kubectl create -f https://raw.githubusercontent.com/csi-addons/kubernetes-csi-addons/v0.8.0/deploy/controller/rbac.yaml kubectl create -f https://raw.githubusercontent.com/csi-addons/kubernetes-csi-addons/v0.8.0/deploy/controller/setup-controller.yaml ``` This creates the required CRDs and configures permissions. To use the features provided by the CSI-Addons, the `csi-addons` containers need to be deployed in the RBD provisioner and nodeplugin pods, which are not enabled by

Execute the following to enable the CSI-Addons sidecars: Update the `rook-ceph-operator-config` configmap and patch the following configuration: ```console kubectl patch cm rook-ceph-operator-config -nrook-ceph -p $'data:\n "CSIENABLECSIADDONS": "true"' ``` After enabling `CSIENABLECSIADDONS` in the configmap, a new sidecar container named `csi-addons` will start automatically in the RBD CSI provisioner and nodeplugin pods. CSI-Addons supports the following operations: Reclaim Space * * Network Fencing Volume Replication * Ceph-CSI supports encrypting individual RBD PersistentVolumeClaims with LUKS. More details can be found including a full list of supported encryption configurations. A sample configmap can be found . !!! note Rook also supports OSD-level encryption (see `encryptedDevice` option ). Using both RBD PVC encryption and OSD encryption at the same time will lead to double encryption and may reduce read/write performance. Existing Ceph clusters can also enable Ceph-CSI RBD PVC encryption support and multiple kinds of encryption KMS can be used on the same Ceph cluster using different storageclasses. The following steps demonstrate how to enable support for encryption: Create the `rook-ceph-csi-kms-config` configmap with required encryption configuration in the same namespace where the Rook operator is deployed. An example is shown below: ```yaml apiVersion: v1 kind: ConfigMap metadata: name: rook-ceph-csi-kms-config namespace: rook-ceph data: config.json: |- { "user-secret-metadata": { "encryptionKMSType": "metadata", "secretName": "storage-encryption-secret" } } ``` Update the `rook-ceph-operator-config` configmap and patch the following configurations ```console kubectl patch cm rook-ceph-operator-config -nrook-ceph -p $'data:\n "CSIENABLEENCRYPTION": "true"' ``` Create the resources (secrets, configmaps etc) required by the encryption type. In this case, create `storage-encryption-secret` secret in the namespace of the PVC as follows: ```yaml apiVersion: v1 kind: Secret metadata: name: storage-encryption-secret namespace: rook-ceph stringData: encryptionPassphrase: test-encryption ``` Create a new with additional parameters `encrypted: "true"` and `encryptionKMSID: "<key used in configmap>"`. An example is show below: ```yaml apiVersion: storage.k8s.io/v1 kind: StorageClass metadata: name: rook-ceph-block-encrypted parameters: encrypted: "true" encryptionKMSID: "user-secret-metadata" ``` PVCs created using the new storageclass will be encrypted. Ceph CSI supports mapping RBD volumes with KRBD options and mounting CephFS volumes with ceph mount options to allow serving reads from an OSD closest to the client, according to OSD locations defined in the CRUSH map and topology labels on nodes. Refer to the for more details. Execute the following step to enable read affinity for a specific ceph cluster: Patch the ceph cluster CR to enable read affinity: ```console kubectl patch cephclusters.ceph.rook.io <cluster-name> -n rook-ceph -p '{"spec":{"csi":{"readAffinity":{"enabled": true}}}}' ``` ```yaml csi: readAffinity: enabled: true ``` Add topology labels to the Kubernetes nodes. The same labels may be used as mentioned in the topic. Ceph CSI will extract the CRUSH location from the topology labels found on the node and pass it though krbd options during mapping RBD volumes. !!! note This requires Linux kernel version 5.8 or higher.