Q:  How can I make an existing virtual machine (VM) a failover cluster resource in Windows Server 2012?

A: If you have VMs on cluster nodes that are not currently cluster resources, it's a simple process to make them highly available, provided they're using cluster storage (such as a Cluster Shared Volume):

  1. Start Failover Cluster Manager.
  2. Expand the cluster Roles.
  3. Select the Configure Role... action.
  4. Click Next to the introduction wizard.
  5. In the Select Role dialog box, select Virtual Machine as the type and click Next.
  6. Select all the virtual machines you want to make highly available and click Next.
  7. Click Next to the confirmation.
  8. Click Finish to the report, which should show Success for all. If there are Warnings, check and resolve problems if needed.