Error
The writer failed due to an error that would likely not occur if the entire backup, restore, or shadow copy creation process was restarted. (VSS_E_WRITERERROR_RETRYABLE)
Cause
This is most often caused by the Microsoft Exchange information store VSS writer being in an unstable state.
Resolution
- Check the exchange backup schedule is set to the recommended settings
- Check the event viewer for any hardware, exchange or resource (lack of RAM or paging file) issues.
- Restart the Microsoft Exchange Information Store service.
- Run “vssadmin list writers” – each writer should now report “State: stable” and “Last error: no error”
- Try the backup again
Note: the exchange VSS writer going regularly into an unstable state could mean underlying hardware, driver or resource issues.
We have seen this issue on machines that are memory overloaded and/or have very slow disk configurations, to properly resolve the issue: a) more RAM should be added to the machine and b) faster disk configuration should be upgraded on the machine.
Further reading
- (Microsoft KB article): Time-out errors occur in Volume Shadow Copy service writers, and shadow copies are lost during backup and during times when there are high levels of input/output. Applies to Windows 2003, however the concepts are similar – VSS requires complex interprocess calls which can fail from a component that doesn’t respond in time.