Win11 VSS snapshot creation fails with volsnap semaphore timeout

Question

Windows 11 Pro 25H2

OS build 26200.7840

Issue Description

Volume Shadow Copy Service (VSS) fails to create snapshots on the system drive (C:). System Restore hangs indefinitely.

Manual snapshot creation using WMIC either hangs or returns ReturnValue = 9. In some cases, the operation times out.

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Observed Errors

Event Viewer logs contain the following entries:

VSS Event ID 12289

volsnap Event ID 67

volsnap Event ID 30

Reported error code:

0x80070079 — The semaphore timeout period has expired.

The snapshot process stalls during the EndPrepareSnapshots phase.

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System State Verification

The system integrity was verified:

DISM RestoreHealth completed successfully. SFC reported no integrity violations. CHKDSK scan reported no file system errors.

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VSS Configuration

All VSS writers report Stable state. Shadow storage configuration is valid. Shadow storage was resized to 30 GB on volume C:. The Microsoft Software Shadow Copy Provider is used.

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Service State During Testing

During reproduction of the issue, the following services were fully stopped and confirmed as stopped:

AppXSVC (AppX Deployment Service) ClipSVC (Client License Service) InstallService (Microsoft Store Install Service)

No AppXDeploymentServer or wsappx processes were running at the time of testing.

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Active Minifilter Drivers

While reproducing the issue, the following minifilter drivers were loaded:

mrigflt WdFilter gameflt

No third-party antivirus or filter drivers are present. Previously installed third-party security software was fully removed.

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Storage State

The system volume uses NTFS. Disk health is normal. Sufficient free space is available. No I/O or SMART errors are reported.

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Reproducibility

The issue is consistently reproducible when attempting to create a shadow copy of volume C:.

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Request for Assistance

We request analysis of the root cause of the VSS snapshot failure under the described conditions and guidance on how to restore normal VSS functionality.

Please advise on any additional diagnostics, logs, or data required to proceed with investigation.

Answer 1

Requesting a human responder / escalation; the current reply is AI-generated and repeats already completed steps

All standard checks listed above have already been completed prior to opening this case, and the issue persists.

Please advise which specific additional diagnostics you recommend collecting in this scenario (for example, exact VSS, volsnap, storage, or kernel tracing), and provide guidance on how to collect them.

If this requires escalation to a Windows client storage / VSS specialist, please proceed accordingly.

Answer 2

Requesting a human responder / escalation; the current reply is AI-generated and repeats already completed steps

Answer 3

I have already completed the checks listed above before posting:

DISM RestoreHealth, SFC, and CHKDSK completed successfully (no corruption / no file system errors).

VSS writers are Stable.

Shadow storage is correctly configured and has been resized to 30 GB.

Disk health and free space are normal.

The issue reproduces consistently.

During testing, AppXSVC (AppX Deployment Service), ClipSVC (Client License Service), and InstallService (Microsoft Store Install Service) were stopped and confirmed STOPPED; no AppXDeploymentServer or wsappx processes were running.

While reproducing the issue, the following minifilter drivers were loaded: mrigflt, WdFilter, gameflt.

No third-party antivirus or filter drivers are present; previously installed third-party security software has been fully removed.

At this stage, I am looking for guidance on the next diagnostic steps (what specific logs/traces to collect) and/or escalation to the appropriate Windows client storage / VSS engineering support, as the problem persists despite all standard checks.

Answer 4

All listed checks have already been completed prior to opening this case.

System integrity (DISM, SFC, CHKDSK) has been verified and reports no issues.

All VSS writers report Stable state.

Shadow storage is correctly configured and has been resized.

Disk health and file system state are confirmed healthy.

The issue reproduces with AppX and Store services stopped.

No third-party antivirus or filter drivers are present.

The issue is consistently reproducible.

At this point, the problem appears to occur below the VSS service layer.

Please advise on next-level diagnostics (for example, specific VSS, volsnap, or kernel logging) or escalate this case for further analysis.

Answer 5

The issue you are experiencing with the Volume Shadow Copy Service (VSS) failing to create snapshots and the associated errors, particularly the semaphore timeout (0x80070079), can be attributed to several potential causes. Here are some steps and considerations to help diagnose and possibly resolve the problem:

1. Resource Availability: Since VSS operations can be sensitive to system resource availability, ensure that there are no other processes consuming excessive CPU or memory during the snapshot creation. You may want to monitor system performance while attempting to create a snapshot.
2. VSS Writer Status: Although you mentioned that all VSS writers report a stable state, it can be beneficial to double-check this by running the command vssadmin list writers in an elevated command prompt. Ensure that all writers are listed without errors.
3. Shadow Storage Configuration: You noted that shadow storage is configured and resized to 30 GB. Ensure that this space is not being exhausted during the snapshot process. You might consider increasing the shadow storage size temporarily to see if it resolves the issue.
4. Event Viewer Logs: The specific Event IDs you mentioned (12289 for VSS and 67, 30 for volsnap) can provide more context. Event ID 12289 indicates a problem with the VSS service, while volsnap errors may point to issues with the volume itself. Investigate these logs further for any additional error messages or warnings that could indicate the root cause.
5. Disk Health and File System: You confirmed that the disk health is normal and that there are no file system errors. However, it might be worth running a more thorough disk check or using tools like chkdsk /f to ensure there are no hidden issues.
6. Minifilter Drivers: The loaded minifilter drivers (mrigflt, WdFilter, gameflt) should be examined to ensure they are not interfering with VSS operations. If possible, try disabling these drivers temporarily to see if it affects the snapshot creation.
7. System Restore Configuration: Since System Restore hangs indefinitely, check the System Protection settings for the C: drive. Ensure that System Restore is enabled and configured correctly, as misconfigurations can affect VSS operations.
8. Windows Updates and Patches: Ensure that your Windows 11 installation is fully updated. Sometimes, specific updates can resolve underlying issues with system services like VSS.

If these steps do not resolve the issue, consider gathering additional logs or diagnostics, such as VSS debug logs, which can provide deeper insights into what might be causing the failures. You may also want to consult Microsoft support for more specialized assistance.

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References:

• Troubleshoot System State Backup
• Usability limit for Volume Shadow Copy Service (VSS)
• System state backup by using Windows Server Backup fails with error: System writer is not found in the backup