I have a Windows Server 2012 "host" server that is running Hyper-V. It is running two Hyper-V virtual machines, both also Windows 2012 servers. I am using the built in Windows Server Backup feature running on the host to backup these virtual machines to an NTFS formatted drive which the host connects to via iSCSI.
If I select to backup just the virtual machines and host component using the "Hyper-V" selection in Windows Server Backup, then the backups are always full (i.e. not incremental), even when Windows Server Backup is configured for Faster Backup Performance.
However, if I select to also backup the volume that the virtual machines are held on (i.e. backup the virtual hard disk files etc.), then that volume is backed up incrementally. Further to that, the Virtual Machine backups (as selected under the "Hyper-V" selection in Windows Server Backup) then happen almost instantly, I'm guessing because the files that comprise their backup (e.g. the virtual hard disk files and VM configuration files) have already been backed up. The summary of the backup job still reports that the backup type as full, but the amount of data transferred is 0kb. It reports a 56MB incremental backups for the D: volume that the Virtual Machines (VHDs and config files) are stored on. The log file for the backup just mentions that the backup of volume D: was successful, and states information about the application backup for the Virtual Machines.
I guess, at the end of the day, I've just got two simple questions:
- Is it possible to do incremental backups of Hyper-V guests using the built in Windows Server 2012 backup feature by just selecting the Hyper-V component and the virtual machines when selecting what to backup?
- Is backing up the volumes the VMs are stored on in conjunction with selecting the VMs under Hyper-V in the backup selection an OK way to achieve incremental backups if 1 is not possible.
Many thanks for any help anyone can provide.