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

1. Check the exchange backup schedule is set to the recommended settings
2. Check the event viewer for any hardware, exchange or resource (lack of RAM or paging file) issues.
3. Restart the Microsoft Exchange Information Store service.
4. Run “vssadmin list writers” – each writer should now report “State: stable” and “Last error: no error”
5. 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.

Error

[com.ahsay.afc.microsoft.MSExchangeExpt] The writer operation failed because of a time-out between the Freeze and Thaw event.  (VSS_E_WRITERERROR_TIMEOUT)

Cause

The exchange VSS writer has gone into a inconsistent state. If this issue occurs regularly it may indicate an underlying hardware issue or lack of resources (ie. system RAM).

The output of vssadmin list writers may look similar to:

Writer name: ‘Microsoft Exchange Writer’
Writer Id: {76fe1ac4-15f7-4bcd-987e-8e1acb462fb7}
Writer Instance Id: {088e9271-a67d-4bd4-82c6-b4b20c59fff4}
State: [9] Failed
Last error: Timed out

Resolution

1. Check to determine whether the Exchange VSS writer state is showing as “stable”. If the writer is not stable, check the event log for hardware/disk events
2. Restart the Microsoft Information Store service
3. Run vssadmin list writers again and confirm that the exchange VSS writer is now stable