Q: If I use shared VHDX in Windows Server 2012 R2 can I still create host level backups, create checkpoints and use Hyper-V Replica?

A: For Windows Server 2012 R2, any feature that leverages the VSS integration services will not work with shared VHDX. Consider the nature of the VSS integration service, which allows the OS using the virtual hard disk (VHD) to take actions to ensure the contents of the disk are in a consistent state.

If multiple virtual machines (VMs) are using a single VHDX file, this makes that type of coordinated quiescing of writes very difficult. This means that for Windows Server 2012 R2, the following features will not work for shared VHDX files:

  • Host level backups (to back up the content of a shared VHDX you should perform the backup within the VM)
  • Checkpoints (formally called snapshots)
  • Hyper-V Replica
  • Storage Migration

On the plus side, although these features don't work, they also don't work for other cluster-shared storage technologies such as iSCSI and virtual fibre channel, so you aren't losing any functionality using shared VHDX. Indeed, you gain the benefit of abstraction of the shared storage from the physical fabric.