Backup Exec 2012 SP4. The job backing up VMs from a VMware ESXi 5.5 cluster with Application GRT had been bugging me for weeks with error:
V-79-57344-38260 - Unable to create a snapshot of the virtual machine. The virtual machine may be too busy to quiesce to take the snapshot.
on one of the VMs which had previously been backed up just fine. For all other VMs it continued working as before.
I finally found the reason and thought I'd share it here, as it didn't figure in the search results I got when searching for this error.
The VM in question had been renamed in vSphere, but not in Windows, and the selection list of the backup job had not been updated. So Backup Exec tried to back up a VM which according to VMware did not exist, but a Windows host by that name did exist, had a Backup Exec agent installed, and even had a valid trust relationship. Apparently that situation confused Backup Exec to such a point it was unable to report the problem correctly.
After removing the VM from the selection list and re-adding it from the browse tree under its new name, it is now backed up fine again. The differing Windows hostname doesn't seem to bother Backup Exec. It even shows the Windows host as "backed up" in the All Servers pane.
Hope it helps someone.
Just for info if you rename any objects in a backup environment and these objects are individually selected in backup jobs then the selection lists MUST be recreated/edited.
This is not specific to VMware as renaming a folder on a drive letter can have the same effect, if the folder was specifically selected in a backup selection. However in the VMware environment please be aware that renaming the folder the server is placed in can have the same effect as renaming the VMware name of the server itself (in terms of what Backup Exec has in a selection list)
Also the VMware names are not directly linked to the hostname of the Virtual machine - this linkage is provided via requests through VMware tools to give the true DNS hostname of the VM. As such BE was really working as designed where it was told to access a VMname that no longer existed and once you fixed the VMname in the selections, yes we would pick up the correct DNS name for the VM.
Absolutely. Not recreating the selection list after the VM was renamed was a mistake which caused the error. (In fact it was a process error because the VMware guy who made that change didn't even inform the backup people about it.)
My posting was about interpreting the IMHO somewhat misleading error message Backup Exec emitted in that situation. I seem to remember that in earlier cases of renamed or deleted VMs, Backup Exec actually produced a helpful message, perhaps even going as far as explicitly stating "no VM found by this name". This time it reported "could not create snapshot" instead, which seemed to imply that it had actually found the VM and tried to create a snapshot for it. In my astonishment about that incongrous message I speculated that might be because it actually found something by that name.