6.4. Reinstalling Hosts
Reinstall Red Hat Virtualization Hosts (RHVH) and Red Hat Enterprise Linux hosts from the Administration Portal. The procedure includes stopping and restarting the host.
- If migration is enabled at cluster level, virtual machines are automatically migrated to another host in the cluster; as a result, it is recommended that host reinstalls are performed at a time when the host’s usage is relatively low.
- Ensure that the cluster has sufficient memory reserve in order for its hosts to perform maintenance. If a cluster lacks sufficient memory, the virtual machine migration operation will hang and then fail. You can reduce the memory usage of this operation by shutting down some or all virtual machines before moving the host to maintenance.
- Ensure that the cluster contains more than one host before performing a reinstall. Do not attempt to reinstall all the hosts at the same time, as one host must remain available to perform Storage Pool Manager (SPM) tasks.
- Click Compute → Hosts and select the host.
- Click Management → Maintenance.
- Click Installation → Reinstall to open the Install Host window.
- Click the Hosted Engine tab and select DEPLOY from the drop-down list.
- Click OK to reinstall the host.
Once successfully reinstalled, the host displays a status of Up. Any virtual machines that were migrated off the host can now be migrated back to it.
After a Red Hat Virtualization Host is successfully registered to the Red Hat Virtualization Manager and then reinstalled, it may erroneously appear in the Administration Portal with the status of Install Failed. Click Management → Activate, and the host will change to an Up status and be ready for use.
After reinstalling the self-hosted engine nodes, you can check the status of the new environment by running the following command on one of the nodes:
# hosted-engine --vm-status
During the restoration, the old self-hosted engine storage domain was renamed, but was not removed from the new environment in case the restoration was faulty. After confirming that the environment is running normally, you can remove the old self-hosted engine storage domain.