Having some issues with a new Hyper-V setup and tape backups. We have a Windows Server 2008 R2 system with Hyper-V role running an SBS 2011 VM and Server 2008 R2 (terminal services) VM.
We are running into some issues with Backup Exec. It appears to be backing up the host system OK but then fails backing up the virtual machines. The error we're seeing is:
Error category : Resource Errors
Error : a0009650 - A snapshot could not be created. The most probable cause is a disk signature collision between two or more VHDs that are assigned to the virtual machine.
For additional information regarding this error refer to link V-79-40960-38480
I've spend a considerable amount of time with Symantec support trying to troubleshoot this issue. Have checked disk signatures on the host and virtual machines, all checks out OK. We've attached the 2 VHDs for the VMs to the host disk management to reset any issues and this came back clear. I've configured a backup in Windows Server Backup to run to an external HDD and this has failed also.
Checking VSS status shows that the 'Microsoft Hyper-V VSS Writer' is in State:  Stable, Last error: Unexpected error
The 'ASR Writer' has also occasionally fallen over. Symantec support have told me that it's looking more like an issue with VSS generally than an issue with Backup Exec (considering Windows backup also fails).
The system was installed a few months ago and Backup Exec has not worked from day 1. Backup Exec System Recovery has also been running from day 1 on a different schedule and this has worked flawlessly backing up to another external HDD.