Chapter 5. Executing the restore procedure

If an error occurs during an update or upgrade, you can restore either the undercloud or overcloud control plane nodes or both so that they assume their previous state.

Use the following general steps:

  1. Burn the bootable ISO image to a DVD or load it through ILO remote access.
  2. Boot the node that requires restoration from the recovery medium.
  3. Select Recover <hostname>, where <hostname> is the name of the node to restore.
  4. Log in as user root.
  5. Recover the backup.

5.1. Restoring the undercloud

If an error occurs during a fast-forward upgrade, you can restore the undercloud node to its previously saved state using the ISO image created using the Section 4.2, “Backing up the undercloud” procedure. The backup procedure stores the ISO images on the backup node in the folders created during the Section 2.2, “Creating and exporting the backup directory” step.

Procedure

  1. Shutdown the undercloud node. Ensure that the undercloud node is shutdown completely before you proceed.
  2. Restore the undercloud node by booting it with the ISO image created during the backup process. The ISO image is located under the /ctl_plane_backups directory of the Backup node.
  3. When the Relax-and-Recover boot menu appears, select Recover <Undercloud Node> where <Undercloud Node> is the name of the undercloud node.

  4. Log in as user root.

    The following message displays: 

    Welcome to Relax-and-Recover. Run "rear recover" to restore your system!
RESCUE <Undercloud Node>:~ # rear recover

    The image restore progresses quickly. When it is complete, the console echoes the following message: 

    Finished recovering your system
Exiting rear recover
Running exit tasks

  5. When the command line interface is available, the image is restored. Switch the node off. 

    RESCUE <Undercloud Node>:~ #  poweroff

    On boot up, the node resumes with its previous state.

5.2. Restoring the control plane

If an error occurs during a fast-forward upgrade, you can use the ISO images created using the Section 4.3, “Backing up the control plane” procedure to restore the control plane nodes to their previously saved state. To restore the control plane, you must restore all control plane nodes to the previous state to ensure state consistency.

Note

Red Hat supports backups of Red Hat OpenStack Platform with native SDNs, such as Open vSwitch (OVS) and the default Open Virtual Network (OVN). For information about third-party SDNs, refer to the third-party SDN documentation.

  1. Shutdown each control plane node. Ensure that the control plane nodes are shutdown completely before you proceed.
  2. Restore the control plane nodes by booting them with the ISO image that you created during the backup process. The ISO images are located under the /ctl_plane_backups directory of the backup node.

  3. When the Relax-and-Recover boot menu appears, select Recover <Control Plane Node> where <Control Plane Node> is the name of the control plane node.

    The following message displays: 

    Welcome to Relax-and-Recover. Run "rear recover" to restore your system!
RESCUE <Control Plane Node>:~ # rear recover

    The image restore progresses quickly. When the restore completes, the console echoes the following message: 

    Finished recovering your system
Exiting rear recover
Running exit tasks

    When the command line interface is available, the image is restored. Switch the node off. 

    RESCUE <Control Plane Node>:~ #  poweroff

    Set the boot sequence to the normal boot device. On boot up, the node resumes with its previous state.

  4. To ensure that the services are running correctly, check the status of pacemaker. Log in to a controller as root user and run the following command: 

    # pcs status
  5. To view the status of the overcloud, use Tempest. For more information about Tempest, see Chapter 4 of the OpenStack Integration Test Suite Guide.