A Full Exchange backup was always failing with a "Snapshot consistency check failed" error message on Saturdays, but not during the week.
The NetVault environment details:Additional non NetVault Backup Software was running snapshot backups at the same time as the scheduled Saturday NetVault backups.
So the VSS components were stretched at the time of the NetVault Exchange backup and advised to schedule both backups to run at different times and making sure that both backups didn't overlap each other.
The "Snapshot consistency check failed" error message didn't reappear.
Here are some further items you can check when experiencing VSS backup issues...
IMPORTANT: The below information is provided as a general guidance and Quest Software, are not liable for any problem that arises following Microsoft configuration changes.
You should seek Microsoft expert advice to perform any Microsoft related troubleshooting or configuration change, and we recommend opening a case with Microsoft.
1] Make sure the machine is patched with latest SP and VSS roll-up patches.
2] Check space: 30% free is needed for snapshots.
3] Memory fragmentation is a cause of VSS issues, so reboot if possible.
4] Verify VSS shadow copies are enabled for each of the drives to backup. (My Computer > right click drive > Properties > Shadow Copies).
5] Are there any other backups or applications trying to schedule a snapshot at the same time?
6] Run CHKDSK on each drive with the /f switch to fix any errors on the disk.
7] Make sure that the COM+ Event System service is set to Automatic.
8] Make sure Volume Shadow Copy service is set to Manual.
9] Having the Exchange Database residing outside of the Exchange Server on an external device can have an impact as well.
