6.7. Migrating hosts and virtual machines from RHV 4.3 to 4.4

You can migrate hosts and virtual machines from Red Hat Virtualization 4.3 to 4.4 such that you minimize the downtime of virtual machines in your environment.

This process requires migrating all virtual machines from one host so as to make that host available to upgrade to RHV 4.4. After the upgrade, you can reattach the host to the Manager.

Warning

When installing or reinstalling the host’s operating system, Red Hat strongly recommends that you first detach any existing non-OS storage that is attached to the host to avoid accidental initialization of these disks, and with that, potential data loss.

Prerequisites

  • Hosts for RHV 4.4 require Red Hat Enterprise Linux 8.2 or later. A clean installation of Red Hat Enterprise Linux 8.2 or later, or Red Hat Virtualization Host 4.4 is required, even if you are using the same physical machine that you use to run hosts for RHV 4.3.
  • Red Hat Virtualization Manager 4.4 is installed and running.
  • The compatibility level of the data center and cluster to which the hosts belong is set to 4.2 or 4.3. All data centers and clusters in the environment must have the cluster compatibility level set to version 4.2 or 4.3 before you start the procedure.

Procedure

  1. Pick a host to upgrade and migrate that host’s virtual machines to another host in the same cluster. You can use Live Migration to minimize virtual machine downtime. For more information, see Migrating Virtual Machines Between Hosts in the Virtual Machine Management Guide.
  2. Put the host into maintenance mode and remove the host from the Manager. For more information, see Removing a Host in the Administration Guide.
  3. Install Red Hat Enterprise Linux 8.2 or later, or RHVH 4.4. For more information, see Installing Hosts for Red Hat Virtualization in one of the Installing Red Hat Virtualization guides.
  4. Install the appropriate packages to enable the host for RHV 4.4. For more information, see Installing Hosts for Red Hat Virtualization in one of the Installing Red Hat Virtualization guides.
  5. Add this host to the Manager, assigning it to the same cluster. You can now migrate virtual machines onto this host. For more information, see Adding Standard Hosts to the Manager in one of the Installing Red Hat Virtualization guides.

Repeat these steps to migrate virtual machines and upgrade hosts for the rest of the hosts in the same cluster, one by one, until all are running Red Hat Virtualization 4.4.