There is an option in the Virtual Machine Manager called Make this VM highly available. This option is set when the Virtual Machine is placed on a host. Therefore, the option will be grayed out, even when the Virtual Machine is not running. There is a way to work around this problem without having to delete and re-create the Virtual Machine. The Virtual Machine can be migrated. Follow the steps below to do this:

  1. Open the Virtual Machine Manager console.
  2. Right-click the relevant Virtual Machine that you want to make highly-available and select Migrate.
  3. Select the current host from the list for migration.
  4. Click Yes to the prompt asking if you want to make the Virtual Machine highly available.
  5. The path can be changed if needed. Click Next.
  6. Select the network and click Move.
  7. Wait for the migration to complete.