Situation:
Our production MS Windows 2016 DataCenter with HyperV as the primary application serving 12 VMs, mostly Windows 2012/r2 and/or 10 Ent.
ArcServe UDP v7u2 used to perform backups.
ArcServe UDP Agent installed on HyperV server, and agentless backups performed of the VMs.
The backup initiates generation of an AVHDX disk (normal) which is used to capture the deltas since the last backup. The failure is, that the AVHDX should auto-merge with its VHDX parent, however, it fails to do so.
Now, we have a long chain of AVHDX differencing disks for several VHDX on several machines. The backups are successfully generated and files are recoverable.
A query of "vssadmin list writers" shows no errors.
An investigation of Hyper-V-VMMS Event logs shows internal error 0x8007054F and 0x8000FFFF related to AVHDX merge and/or removal of snapshot.
I have a PoSH script that successfully discovers the VM disks currently in use, and merges the AVHDX back into the VHDX. However, this requires the entire chain be copied, and then merged via PoSH script which all takes lots of time. And, then requires
that I build a new VM instance to mount these VHDX disks.
How do I prevent the AVHDX merge failure in the first place? Is there a known KB or other patch to address this?
Thanks!