Details on the High Availability section of the VMs Properties in SCVMM are:
Highly available virtual machine <Machinename> is not supported by VMM because the VM uses non-clustered storage. Ensure that all of the files and pass-through disks belonging to the VM reside on highly available storage.
This limitation only applies if the pass through disk provided from a SAS storage array in a clustered environment is GPT. There are two workarounds for this:
1. Add the LUN from the SAS storage to the cluster, create a CSV and place the VHDs on it and attach those to the VM.
2. Create MBR pass through disks and attach those to the VM. Note that both VHD and MBR pass through disks are limited to 2TB in size.
This will be fixed in the next version of SCVMM.
Article ID: 2525103 - Last Review: May 2, 2011 - Revision: 1