Please use the following steps on Cannot start shadow copy (VSS_E_WRITERERROR_NONRETRYABLE) (MS SQL server with large number of databases).
Symptom:
When performing either a scheduled or manual Microsoft SQL database backup job, the following backup error is received in the backup report:
Cannot start shadow copy, reason =The writer operation failed because of an error that might recur if another shadow copy is created.
(VSS_E_WRITERERROR_NONRETRYABLE)
Cause:
The error message is returned by MS SQL VSS writer, suggesting that there was an insufficient number of worker threads configured on the MS SQL Server to support the backup of all databases selected for backup.
Please refer to the Limitations and Restrictions section in the following article for more details:
Configure the max worker threads
Resolution:
To resolve the issue, either:
Option 1 :
Create additional backup sets (to be performed at different times) for the excess databases.
or
Option 2 :
Increase the maximum number of worker threads on the MS SQL Server.
To configure the max worker threads option:
- In the Object Explorer, right click a server and select Properties.
- Click the Processors node.
- In the Max worker threads box, type or select a value for the max worker thread.
For more details, refer to the following article: Configure the max worker threads
Important
Please consult with an experience database administrator or certified SQL Server technician before making any change to the maximum worker threads.