Q. Should I back up at the Hyper-V host level or within my guest OSs?

A. The answer to this question depends on the guest OS, the type of storage you are using and the availability of VSS writers for the workloads within the virtual machine (VM).

If you're running guest OSs that support VSS, use NTFS on basic disks, exclusively use Virtual Hard Disks (VHDs) for storage, and have integration services installed, you can probably back up safely at the Hyper-V host level. You can use a Hyper-V VSS writer-aware backup application that will notify your VMs to prepare for a snapshot, ensuring the integrity of the backup. Remember to back up all volumes that have any data relating to the VM, including configuration locations, VHDs, and snapshots.

You should back up from within the guest OSs if you're running guest OS that

• Uses pass through storage.
• Maps to iSCSI storage directly through the guest iSCSI initiator.
• Doesn't use NTFS.
• Uses dynamic disks.
• Doesn't have integration services installed or doesn't support the backup integration service.

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