When we back up the Exchange, we create a snapshot with the help of the VSS of Exchange database.
The following actions can lead to the error causing loss of the snapshot:
- Rebooting the server during the backup of exchange.
- Restarting the DataShield Back and Recovery Service Controller during the backup of Exchange.
- Restarting the Microsoft Information Store Service or the VSS during the backup of Exchange.
It's probably that this is a temporary issue and the next backup will be successful.
NOTE: There is also a chance that the system deleted the snapshot by itself.
You should check event logs in the time frame of approximately 10 minutes of the failure.
If it is the case that VolSnap deletes the snapshot, you should tune your system to prevent it.