Write-Back caching policy not allowed for VMs with Duplicate UUIDs
In rare instances, VMs within the same vCenter will share the same BIOS UUID. In this situation, you won’t be able to use Write-Back caching policy either at the Datastore or VM level. You will only be able to use Write-Through caching policy.
Since this is a rare use case and has other issues, outside of VirtuCache, Virtunet doesn’t plan on supporting this use case for Write-Back caching.