Problem

The error: “[Shadow Copy] Snapshot for Shadow Copy Set is missing, backup
terminate.” is seen in the backup report and logs.

Cause

The most common causes of this error are:

1. The computer has gone to sleep or the disk drives have been powered down during the backup.
2. There is a lower-level problem with the physical disk or VSS subsystem.
3. Some other backup software is creating/destroying volume shadow copies during the backup.

Resolution

1. Ensure that the computer power modes have been set to not sleep the computer or power down the disk drives.
2. Check the Windows Event Log for any warnings or errors from the “Disk” source. Also check the output from vssadmin list writers and ensure that all VSS writers are in a stable state.
3. Ensure that no other backup software is running or shadow copies are being created at the time of the backup.