Windows Server · high · Roles & shared services

Backups fail — VSS writer is in a failed state

The Volume Shadow Copy writer for an application failed during the snapshot, so the backup has nothing consistent to copy.

What you see

Backups fail with a VSS error. vssadmin list writers shows one or more writers in a state other than Stable, or with a non-zero last error.

What is actually wrong

A writer timed out under load, the shadow storage area is too small, or a service the writer belongs to is unhealthy. Third-party backup agents frequently leave stale snapshots behind.

Codes and articles

Event 8193Event 12289Event 122930x800423f40x80042306VSS_E_WRITERERROR_TIMEOUTRetryable error

The fix

Identify the failed writer and give the snapshot room to work

Elevated PowerShell45 minutesmedium riskreversible

Any VSS backup failure. Work through in order — restarting services blindly is the usual mistake and it takes the applications with it.

List the writers and their state. Note every one that is not Stable with No error.
Command Prompt
```
vssadmin list writers
```
Check the shadow storage limits. A writer that cannot allocate space fails with a timeout that looks like an application problem.
Command Prompt
```
vssadmin list shadowstorage
```
The default association is often a small percentage of the volume. On a busy file server the snapshot fills it and is deleted mid-backup.
Increase the allocation for the volume being backed up.
Command Prompt
```
vssadmin resize shadowstorage /for=D: /on=D: /maxsize=15%
```
Clear any stale shadow copies left behind by a previous failure.
Command Prompt
```
vssadmin list shadowsvssadmin delete shadows /for=D: /oldest
```
Restart only the service that owns the failed writer — not every VSS service. Map the writer to its service first.
PowerShell
```
Get-Service | Where-Object { $_.Name -in 'VSS','SWPRV','MSDTC','EventSystem','COMSysApp' } | Format-Table Name, DisplayName, Status -AutoSize
```
The System Writer belongs to Cryptographic Services, the Registry Writer to VSS itself, the SQL writer to SQL VSS Writer. Restarting the wrong one interrupts production for nothing.
Restart the specific owning service, then re-check the writers.
Command Prompt
```
Restart-Service CryptSvcvssadmin list writers
```
If writers stay failed, a restart of the server clears every writer state — schedule it rather than doing it blind.

Confirm it workedAll writers report Stable with no error, and a test backup completes.

Command Prompt

vssadmin list writers | findstr /i "writer name state error"

If you need to undo itvssadmin resize shadowstorage back to the previous maxsize if the larger allocation is a problem for capacity.

Related faults

Where this stops. This write-up was written and checked by hand. It says what each step changes, how to confirm it worked and how to reverse it, and anything destructive is flagged before you reach it. If it does not match what your machine is doing, search the Support Centre for the exact code or message — and when something needs a person, get in touch.