Problem Description:
SQL Server backup failed due to VSS error: State: Waiting for completion
Error Code: SQL 43
Cause:
The VSS writer is in an unstable state, waiting for completion, or conflicting with other applications using VSS.
Steps to Resolve the Issue
1. Verify VSS Writer Status
Open Command Prompt with administrative privileges.
Run the command:
vssadmin list writersReview the status of SQL Server Writer:
Stable (No Error): No action needed.
Failed/Unstable: Proceed to the steps below.
In-Progress or Waiting for Completion: Follow resolution steps for this specific state.
2. Fixing Common Writer Issues
A. Writer Status: Failed or Unstable
Restart SQL Server VSS Writer Service:
Open Services (
services.msc).Locate
SQL Server VSS Writer.Stop the service → Wait for 30 seconds → Restart the service.
Re-run
vssadmin list writersto confirm the status is stable.
Restart Volume Shadow Copy Services:
Open Services (
services.msc).Restart the following services:
Volume Shadow CopyMicrosoft Software Shadow Copy Provider
Verify the status again with
vssadmin list writers.
B. Writer Status: In-Progress or Waiting for Completion
Restart SQL Server VSS Writer Service (Repeat steps outlined above).
Restart Volume Shadow Copy Services (Repeat steps outlined above).
Additional Checks:
Review any background processes or tasks that might be locking VSS resources.
3. Review Event Viewer Logs
Open Event Viewer.
Review Application and System logs for related errors:
Common error messages:
"VSS writer error: 0x800423f4"
"Shadow copy creation failed"
Look for Event IDs:
12292,8220.
Use the log details to identify potential conflicting applications or missing configurations.
4. Kill VSS Processes (Advanced Troubleshooting)
Open Task Manager:
Locate and End all VSS-related processes.
Restart
SQL Server VSS Writerservice.Re-run
vssadmin list writersto confirm resolution.
5. Restart the Server
If the issue persists after restarting VSS-related services, perform a server reboot to reset all associated services.
6. Escalation to Windows Support
If the issue remains unresolved:
Escalate to Windows support with the details.
Provide logs from Event Viewer and outputs from
vssadmin list writers.