We 3 Hyper-V hosts on Windows Datacenter 2008, 2 of which backup fine. The 3rd fails, throwing a VSS error for every virtual guest. The ~20 guests themselves do not show VSS errors or anything else of note in the event viewer.
The failing host shows constant VSS warnings in the event viewer:
Volume Shadow Copy Warning: The provider has reported a storage identifier that is not supported by VSS. Codeset: 1 Type: 5 Size: 4 NextOffset: 24 Association: 1 This identifier will be skipped by VSS.
Context:
Examining Detected Volume: Arrival - \\?\STORAGE#Volume#1&19f7e59c&0&Signature4D823883Offset100000Length5780700000#{53f5630d-b6bf-11d0-94f2-00a0c91efb8b}
The backup log errors are the same for every guest:
AOFO: Initialization failure on: "VRTSRV::\\VH4.tesc.edu\Hyper-V?Virtual?Machine\actidx". Advanced O...
V-79-10000-11217 - VSS Snapshot error. The Microsoft Volume Shadow Copy Service (VSS) snapshot failed. Make sure tha...The following volumes are dependent on resource: "E:" .
I assume this is a VSS issue on the host? I have registered the .dll's and the VSSADMIN LIST WRITERS command shows everything is OK. One thing I haven't tried is restarting the host... because that is no easy task...
