mtpti5iD/redhat-docs_dataset huggingface dataset:
Chapter 25. Using VNC The graphical installation interface is the recommended method of installing Red Hat Enterprise Linux. However, in some cases, accessing the graphical interface directly is difficult or impossible. Many enterprise systems, notably servers (IBM Power Systems and IBM Z), lack the capability to connect a display and a keyboard, making VNC a necessity for manual (non-Kickstart) installations. To allow manual installations on headless systems (systems without a directly connected display, keyboard and mouse), the Anaconda installation program includes a Virtual Network Computing (VNC) installation which allows the graphical mode of the installation program to run locally, but display on a system connected to the network. The VNC installation provides you with the full range of installation options, even in situations where the system lacks a display or input devices. This chapter provides instructions on activating VNC mode on the installation system and connecting to it using a VNC viewer. 25.1. Installing a VNC Viewer Performing a VNC installation requires a VNC viewer running on your workstation or another terminal computer. VNC viewers are available in the repositories of most Linux distributions; free VNC viewers are also available for other operating systems such as Windows. On Linux systems, use your package manager to search for a viewer for your distribution. The following VNC viewers are available in Red Hat Enterprise Linux: TigerVNC - A basic viewer independent of your desktop environment. Installed as the tigervnc package. Vinagre - A viewer for the GNOME desktop environment. Installed as the vinagre package. KRDC - A viewer integrated with the KDE desktop environment. Installed as the kdenetwork-krdc package. To install any of the viewers listed above, execute the following command as root : Replace package with the package name of the viewer you want to use (for example, tigervnc ). Note Procedures in this chapter assume you are using TigerVNC as your VNC viewer. Specific instructions for other viewers can differ, but the general principles still apply.

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yum install package
16.2. About READ_COMMITTED READ_COMMITTED is one of two isolation modes available in Red Hat JBoss Data Grid. In JBoss Data Grid's READ_COMMITTED mode, write operations are made to copies of data rather than the data itself. A write operation blocks other data from being written, however writes do not block read operations. As a result, both READ_COMMITTED and REPEATABLE_READ modes permit read operations at any time, regardless of when write operations occur. In READ_COMMITTED mode multiple reads of the same key within a transaction can return different results due to write operations in different transactions modifying data between reads. This phenomenon is known as non-repeatable reads and is avoided in REPEATABLE_READ mode. Report a bug

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6.2.3. Preparing an Initial RAM Disk Update Important This is an advanced procedure that you should consider only if you cannot perform a driver update with any other method. The Red Hat Enterprise Linux installation program can load updates for itself early in the installation process from a RAM disk - an area of your computer's memory that temporarily behaves as if it were a disk. You can use this same capability to load driver updates. To perform a driver update during installation, your computer must be able to boot from a preboot execution environment (PXE) server, and you must have a PXE server available on your network. Refer to Chapter 30, Setting Up an Installation Server for instructions on using PXE during installation. To make the driver update available on your PXE server: Place the driver update image file on your installation server. Usually, you would do this by downloading it to the server from a location on the Internet specified by Red Hat or your hardware vendor. Names of driver update image files end in .iso . Copy the driver update image file into the /tmp/initrd_update directory. Rename the driver update image file to dd.img . At the command line, change into the /tmp/initrd_update directory, type the following command, and press Enter : Copy the file /tmp/initrd_update.img into the directory the holds the target that you want to use for installation. This directory is placed under the /var/lib/tftpboot/pxelinux/ directory. For example, /var/lib/tftpboot/pxelinux/rhel6/ might hold the PXE target for Red Hat Enterprise Linux 6. Edit the /var/lib/tftpboot/pxelinux/pxelinux.cfg/default file to include an entry that includes the initial RAM disk update that you just created, in the following format: Where target is the target that you want to use for installation. Refer to Section 6.3.4, "Select a PXE Target that Includes a Driver Update" to learn how to use an initial RAM disk update during installation. Example 6.1. Preparing an initial RAM disk update from a driver update image file In this example, driver_update.iso is a driver update image file that you downloaded from the Internet to a directory on your PXE server. The target that you want to PXE boot from is located in /var/lib/tftpboot/pxelinux/rhel6/ At the command line, change to the directory that holds the file and enter the following commands: Edit the /var/lib/tftpboot/pxelinux/pxelinux.cfg/default file and include the following entry:

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find . | cpio --quiet -o -H newc | gzip -9 >/tmp/initrd_update.img
label target -dd kernel target /vmlinuz append initrd= target /initrd.img, target /dd.img
cp driver_update.iso /tmp/initrd_update/dd.img cd /tmp/initrd_update find . | cpio --quiet -c -o -H newc | gzip -9 >/tmp/initrd_update.img cp /tmp/initrd_update.img /var/lib/tftpboot/pxelinux/rhel6/dd.img
label rhel6-dd kernel rhel6/vmlinuz append initrd=rhe6/initrd.img,rhel6/dd.img
Chapter 7. Known issues The known issues for running .NET on Red Hat Enterprise Linux (RHEL) include the following: dotnet dev-certs https --trust does not work on RHEL. .NET supports the creation of HTTPS certificate through dotnet dev-certs https , but it does not support trusting them through dotnet dev-certs https --trust . The client that connects to the ASP.NET Core application, such as curl or Firefox, will warn about the untrusted self-signed certificate. To work around this in a browser such as Firefox, ignore the warning and trust the certificate explicitly when the warning about the untrusted certificate comes up. Command-line tools support flags to ignore untrusted certificates. For curl , use the --insecure flag. For wget , use the --no-check-certificate flag. There are no NuGet packages for ppc64le and s390x on nuget.org. Using the rhel.8-s390x , linux-s390x , rhel.8-ppc64le , or linux-ppc64le runtime identifier can cause some dotnet commands to fail when they try to obtain these packages. These commands are either not fully supported on ppc64le and s390x as described in the other known issues, or the issue can be fixed by not specifying the runtime identifier. Single file applications are not supported on ppc64le or s390x . PublishReadyToRun/crossgen is not supported on ppc64le or s390x . OmniSharp, the language server used by IDEs like Visual Studio Code, is not available on ppc64le and s390x . Several workloads not be installed in the .NET 8.0 shipped by Red Hat: android macos maui-android maui-tizen maui-windows

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Appendix B. Revision History 0.2-0 Thu Jan 30 2025, Gabriela Fialova ( gfialova@redhat.com ) Added an Known Issue JIRA:RHELDOCS-19603 (IdM SSSD) 0.1-9 Wed Dec 4 2024, Gabriela Fialova ( gfialova@redhat.com ) Updated the Customer Portal labs section Updated the Installation section 0.1-8 Thu Nov 7 2024, Gabriela Fialova ( gfialova@redhat.com ) Added a Removed functionality JIRA:RHELDOCS-18772 (Desktop). 0.1-7 Thu May 9 2024, Brian Angelica ( bangelic@redhat.com ) Updated Tech Preview in BZ#1690207 . 0.1-6 Fri Nov 10 2023, Gabriela Fialova ( gfialova@redhat.com ) Updated the module on Providing Feedback on RHEL Documentation. 0.1-5 Fri Oct 13 2023, Gabriela Fialova ( gfialova@redhat.com ) Added a Tech Preview JIRA:RHELDOCS-16861 (Containers). 0.1-4 Thu Apr 27 2023, Gabriela Fialova ( gfialova@redhat.com ) Added a known issue JIRA:RHELPLAN-155168 (Identity Management). 0.1-3 Fri Apr 29 2022, Lenka Spackova ( lspackova@redhat.com ) Updated Deprecated functionality introduction. Fixed typo in BZ#1605216 . Fixed broken links. 0.1-2 Thu Mar 17 2022, Lucie Manaskova ( lmanasko@redhat.com ) Added JIRA:RHELPLAN-14323 , JIRA:RHELPLAN-14329 , and JIRA:RHELPLAN-14330 to the New features section (Virtualization). 0.1-1 Thu Dec 23 2021, Lenka Spackova ( lspackova@redhat.com ) Added information about the Soft-RoCE driver, rdma_rxe , to Technology Previews BZ#1605216 and Deprecated functionality BZ#1878207 (Kernel). 0.1-0 Thu Sep 23 2021, Lucie Manaskova ( lmanasko@redhat.com ) Removed an invalid new feature description (Virtualization). 0.0-9 Thu Aug 19 2021, Lucie Manaskova ( lmanasko@redhat.com ) Added the Package management with YUM/DNF to the Distribution chapter. 0.0-8 Wed Jun 23 2021, Lucie Manaskova ( lmanasko@redhat.com ) Updated the New features section (Installer). 0.0-7 Tue Apr 06 2021, Lenka Spackova ( lspackova@redhat.com ) Improved the list of supported architectures. 0.0-6 Thu Jan 28 2021, Lucie Manaskova ( lmanasko@redhat.com ) Updated the Technology Previews chapter. 0.0-5 Thu Dec 10 2020, Lenka Spackova ( lspackova@redhat.com ) Added information about handling AD GPOs in SSSD to New features (Identity Management). 0.0-4 Tue Apr 28 2020, Lenka Spackova ( lspackova@redhat.com ) Updated information about in-place upgrades in Overview. 0.0-3 Thu Mar 12 2020, Lenka Spackova ( lspackova@redhat.com ) Added the missing postfix RHEL system role to Technology Previews. 0.0-2 Wed Feb 12 2020, Jaroslav Klech ( jklech@redhat.com ) Provided a complete kernel version to Architectures and New Features chapters. 0.0-1 Tue Jul 30 2019, Lucie Manaskova ( lmanasko@redhat.com ) Release of the Red Hat Enterprise Linux 8.0.1 Release Notes. 0.0-0 Tue May 07 2019, Ioanna Gkioka ( igkioka@redhat.com ) Release of the Red Hat Enterprise Linux 8.0 Release Notes.

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Chapter 14. Activating the subscriptions service If the subscriptions service is not activated by one of the tasks that include automatic activation, then the subscriptions service must be manually activated. Tasks that include automatic activation are purchasing an On-Demand subscription through Red Hat Marketplace or creating an Amazon Web Services or Microsoft Azure integration that includes the RHEL management bundle through the integrations service in the Hybrid Cloud Console. If manual activation is needed, the subscriptions service must be activated by a user with access to the Red Hat account and organization through a Red Hat Customer Portal login. This login is not required to be a Red Hat Customer Portal Organization Administrator (org admin). In addition, that user must also have the Subscriptions administrator role or the Subscriptions viewer role in the user access role-based access control (RBAC) system for console.redhat.com. Note If a Red Hat Customer Portal login is associated with an organization that does not have an account relationship with Red Hat, then the subscriptions service cannot be activated. When the subscriptions service is activated, the Hybrid Cloud Console tools begin analyzing and processing data from the data collection tools for display in the subscriptions service. Note The following procedure guides you through the steps to activate the subscriptions service from console.redhat.com. If the subscriptions service is not already activated, you can also access the activation page at the conclusion of the subscriptions service tour. Procedure In a browser window, go to console.redhat.com . If prompted, enter your Red Hat Customer Portal login credentials. In the Hybrid Cloud Console dashboard, click Services and then click Subscriptions and Spend in the navigation panel. On the Subscriptions and Spend page, click the Overview option for Subscription Services. In the navigation panel of the Subscription Services page, expand Subscriptions Usage. Click one of the Red Hat platform options, Red Hat Enterprise Linux , OpenShift , or Ansible , to check the status of the subscriptions service for your Red Hat account and organization. Complete one of the following steps, depending on the status of the subscriptions service activation: If the subscriptions service is not yet active for the account, the activation page displays. Click Activate Subscriptions . If the subscriptions service is activated but not yet ready to display data, the subscriptions service application opens, but it displays an empty graph. Try accessing the subscriptions service later, typically the day. If the subscriptions service is activated and the initial data processing is complete, the subscriptions service application opens and displays data on the graph. You can begin using the subscriptions service to view data about subscription usage and capacity for the account. Verification steps Data processing for the initial display of the subscriptions service can take up to 24 hours. Until data for the account is ready, only an empty graph will display.

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probe::ioscheduler.elv_add_request Name probe::ioscheduler.elv_add_request - probe to indicate request is added to the request queue. Synopsis ioscheduler.elv_add_request Values rq Address of request. q Pointer to request queue. elevator_name The type of I/O elevator currently enabled. disk_major Disk major no of request. disk_minor Disk minor number of request. rq_flags Request flags.

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Network APIs OpenShift Container Platform 4.12 Reference guide for network APIs Red Hat OpenShift Documentation Team

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Name: "mysvc", Subsets: [ { Addresses: [{"ip": "10.10.1.1"}, {"ip": "10.10.2.2"}], Ports: [{"name": "a", "port": 8675}, {"name": "b", "port": 309}] }, { Addresses: [{"ip": "10.10.3.3"}], Ports: [{"name": "a", "port": 93}, {"name": "b", "port": 76}] }, ]
Name: "mysvc", Subsets: [ { Addresses: [{"ip": "10.10.1.1"}, {"ip": "10.10.2.2"}], Ports: [{"name": "a", "port": 8675}, {"name": "b", "port": 309}] }, { Addresses: [{"ip": "10.10.3.3"}], Ports: [{"name": "a", "port": 93}, {"name": "b", "port": 76}] }, ]
{ Addresses: [{"ip": "10.10.1.1"}, {"ip": "10.10.2.2"}], Ports: [{"name": "a", "port": 8675}, {"name": "b", "port": 309}] }
a: [ 10.10.1.1:8675, 10.10.2.2:8675 ], b: [ 10.10.1.1:309, 10.10.2.2:309 ]
2.5.4.2. The mpstat command The mpstat command produces the following output: On multiprocessor systems, mpstat allows the utilization for each CPU to be displayed individually, making it possible to determine how effectively each CPU is being used.

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Linux 2.6.11-1.1369_FC4 (example.redhat.com) 02/07/2006 01:22:23 PM CPU %user %nice %system %iowait %irq %soft %idle intr/s 01:22:23 PM all 0.02 0.00 0.02 0.02 0.02 0.00 99.92 1011.86
6.4. Replacing a Missing Physical Volume If a physical volume fails or otherwise needs to be replaced, you can label a new physical volume to replace the one that has been lost in the existing volume group by following the same procedure as you would for recovering physical volume metadata, described in Section 6.3, "Recovering Physical Volume Metadata" . You can use the --partial and --verbose arguments of the vgdisplay command to display the UUIDs and sizes of any physical volumes that are no longer present. If you wish to substitute another physical volume of the same size, you can use the pvcreate command with the --restorefile and --uuid arguments to initialize a new device with the same UUID as the missing physical volume. You can then use the vgcfgrestore command to restore the volume group's metadata.

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Chapter 3. Technology Previews Important Technology Preview features are not supported with Red Hat production service-level agreements (SLAs) and might not be functionally complete; therefore, Red Hat does not recommend implementing any Technology Preview features in production environments. This Technology Preview feature provides early access to upcoming product innovations, enabling you to test functionality and provide feedback during the development process. For more information about support scope, see Technology Preview Features Support Scope . 3.1. Cruise Control for cluster rebalancing Note Cruise Control remains in Technology Preview, with some new enhancements . You can install Cruise Control and use it to rebalance your Kafka cluster using optimization goals - defined constraints on CPU, disk, network load, and more. In a balanced Kafka cluster, the workload is more evenly distributed across the broker pods. Cruise Control helps to reduce the time and effort involved in running an efficient and balanced Kafka cluster. A zipped distribution of Cruise Control is available for download from the Customer Portal . To install Cruise Control, you configure each Kafka broker to use the provided Metrics Reporter. Then, you set Cruise Control properties, including optimization goals, and start Cruise Control using the provided script. The Cruise Control server is hosted on a single machine for the whole Kafka cluster. When Cruise Control is running, you can use the REST API to: Generate dry run optimization proposals from multiple optimization goals Initiate an optimization proposal to rebalance the Kafka cluster Other Cruise Control features are not currently supported, including anomaly detection, notifications, write-your-own goals, and changing the topic replication factor. See Cruise Control for cluster rebalancing . 3.1.1. Enhancements to the Technology Preview The following enhancements have been added to the Technology Preview of Cruise Control for cluster rebalancing. New goal: Minimum topic leaders per broker You can use a new goal named MinTopicLeadersPerBrokerGoal . For each topic in a defined group of topics, the goal ensures that each active broker has at least a certain number of leader replicas. MinTopicLeadersPerBrokerGoal is a default goal and is preset as a hard goal. See Optimization goals overview Logging enhancement: Log4j 2 Log4j 2 is now used for Cruise Control logging. You must update existing configurations for Cruise Control logging (in /opt/cruise-control/config/log4j.properties ) from Log4j to Log4j 2 compatible syntax. See Cruise Control configuration

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7.3. Creating a Template Create a template from an existing virtual machine to use as a blueprint for creating additional virtual machines. Note In RHV 4.4, to seal a RHEL 8 virtual machine for a template, its cluster level must be 4.4 and all hosts in the cluster must be based on RHEL 8. You cannot seal a RHEL 8 virtual machine if you have set its cluster level to 4.3 so it can run on RHEL 7 hosts. When you create a template, you specify the format of the disk to be raw or QCOW2: QCOW2 disks are thin provisioned. Raw disks on file storage are thin provisioned. Raw disks on block storage are preallocated. Creating a Template Click Compute Virtual Machines and select the source virtual machine. Ensure the virtual machine is powered down and has a status of Down . Click More Actions ( ), then click Make Template . For more details on all fields in the New Template window, see Explanation of Settings in the New Template and Edit Template Windows . Enter a Name , Description , and Comment for the template. Select the cluster with which to associate the template from the Cluster drop-down list. By default, this is the same as that of the source virtual machine. Optionally, select a CPU profile for the template from the CPU Profile drop-down list. Optionally, select the Create as a Template Sub-Version check box, select a Root Template , and enter a Sub-Version Name to create the new template as a sub-template of an existing template. In the Disks Allocation section, enter an alias for the disk in the Alias text field. Select the disk format in the Format drop-down, the storage domain on which to store the disk from the Target drop-down, and the disk profile in the Disk Profile drop-down. By default, these are the same as those of the source virtual machine. Select the Allow all users to access this Template check box to make the template public. Select the Copy VM permissions check box to copy the permissions of the source virtual machine to the template. Select the Seal Template check box (Linux only) to seal the template. Note Sealing, which uses the virt-sysprep command, removes system-specific details from a virtual machine before creating a template based on that virtual machine. This prevents the original virtual machine's details from appearing in subsequent virtual machines that are created using the same template. It also ensures the functionality of other features, such as predictable vNIC order. See virt-sysprep operations for more information. Click OK . The virtual machine displays a status of Image Locked while the template is being created. The process of creating a template may take up to an hour depending on the size of the virtual disk and the capabilities of your storage hardware. When complete, the template is added to the Templates tab. You can now create new virtual machines based on the template. Note When a template is made, the virtual machine is copied so that both the existing virtual machine and its template are usable after template creation.

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Chapter 1. General Introduction to Virtualization 1.1. What is Virtualization? Virtualization is a broad computing term used for running software, usually multiple operating systems, concurrently and in isolation from other programs on a single system. Virtualization is accomplished by using a hypervisor . This is a software layer or subsystem that controls hardware and enables running multiple operating systems, called virtual machines (VMs) or guests , on a single (usually physical) machine. This machine with its operating system is called a host . There are several virtualization methods: Full virtualization Full virtualization uses an unmodified version of the guest operating system. The guest addresses the host's CPU using a channel created by the hypervisor. Because the guest communicates directly with the CPU, this is the fastest virtualization method. Paravirtualization Paravirtualization uses a modified guest operating system. The guest communicates with the hypervisor. The hypervisor passes the unmodified calls from the guest to the CPU and other interfaces, both real and virtual. Because the calls are routed through the hypervisor, this method is slower than full virtualization. Software virtualization (or emulation) Software virtualization uses binary translation and other emulation techniques to run unmodified operating systems. The hypervisor translates the guest calls to a format that can be used by the host system. Because all calls are translated, this method is slower than virtualization. Note that Red Hat does not support software virtualization on Red Hat Enterprise Linux. For information about the benefits of using virtualization, see Chapter 2, Why Use Virtualization?

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