Should I be concerned about this error in Veeam:
Freezing guest operating system
VSSControl: Failed to freeze guest, wait timeout
It seems to be proceeding with the backups. What does this error mean?
SnapOverflow
AdamF, It appears that you may be attempting to backup the vCenter SQL Server, this is a common error that occurs because the VSS operation can freeze SQL because vCenter has control of it. There are work-arounds, I recommend you take a look at the Veeam forums and search for this specific VSS error. http://forums.veeam.com