5.6. Updating the Hosts
Use this procedure to update Red Hat Enterprise Linux hosts or Red Hat Virtualization Hosts (RHVH).
Legacy Red Hat Enterprise Virtualization Hypervisors (RHEV-H) are not supported in Red Hat Virtualization; you must reinstall them with RHVH. See Installing Red Hat Virtualization Host in the Installation Guide. If you need to preserve local storage on the host, see Appendix C, Upgrading from RHEV-H 3.6 to RHVH 4.2 While Preserving Local Storage.
If you are not sure whether you are using RHEV-H or RHVH, type imgbase check. If the command fails, the host is RHEV-H. If it succeeds, the host is RHVH.
Use the host upgrade manager to update individual hosts directly from the Red Hat Virtualization Manager.
The upgrade manager only checks hosts with a status of Up or Non-operational, but not Maintenance.
On RHVH, the update only preserves modified content in the /etc and /var directories. Modified data in other paths is overwritten during an update.
Prerequisites
- If migration is enabled at the cluster level, virtual machines are automatically migrated to another host in the cluster. Update a host when its usage is relatively low.
- Ensure that the cluster contains more than one host before performing an update. Do not update all hosts at the same time, as one host must remain available to perform Storage Pool Manager (SPM) tasks.
- Ensure that the cluster to which the host belongs has sufficient memory reserve for its hosts to perform maintenance. Otherwise, the virtual machine migration operation will hang and fail. You can reduce the memory usage of this operation by shutting down some or all virtual machines before updating the host.
- You cannot migrate a virtual machine using a vGPU to a different host. Virtual machines with vGPUs installed must be shut down before updating the host.
Procedure
If your Red Hat Enterprise Linux hosts are locked to version 7.3, as described in https://access.redhat.com/solutions/3194482, set them to the general RHEL 7 version before updating (to view the version number, type
subscription-manager release --show):# subscription-manager release --set=7Server
Disable your current repositories:
# subscription-manager repos --disable='*'
Ensure that the correct repositories are enabled (to view a list of currently enabled repositories, type
yum repolist):For Red Hat Virtualization Hosts:
# subscription-manager repos --enable=rhel-7-server-rhvh-4-rpms
For Red Hat Enterprise Linux hosts:
# subscription-manager repos \ --enable=rhel-7-server-rpms \ --enable=rhel-7-server-rhv-4-mgmt-agent-rpms \ --enable=rhel-7-server-ansible-2.9-rpms
-
In the Administration Portal, click
and select the host to be updated. Click
and click . Click the Events and alerts notification icon (
) and expand the Events section to see the result.
-
If an update is available, click
. Click to update the host. Running virtual machines will be migrated according to their migration policy. If migration is disabled for any virtual machines, you will be prompted to shut them down.
The details of the host are updated in
and the status transitions through these stages: - Maintenance
- Installing
- Reboot
Up
If any virtual machines were migrated off the host, they are now migrated back.
NoteIf the update fails, the host’s status changes to Install Failed. From Install Failed you can click
again.
Repeat this procedure for each host in the Red Hat Virtualization environment.
