Quiesced snapshot creation on SQL VMs fails with the error: "Failed to quiesce the virtual machine"

Products

• VMware vSphere ESXi

Issue/Introduction

• Quiesced snapshots on the SQL VM/s are failing, and the snapshots are not being created. The error message is as follows:

  Create virtual machine snapshot - VM_Name
  
  An error occurred while quiescing the virtual machine. See the virtual machine's event log for details. 
  An error occurred while taking a snapshot: Failed to quiesce the virtual machine. An error occurred while saving the snapshot: Failed to quiesce the virtual machine.

• The issue is observed only when application-consistent SQL snapshots are taken using VSS; regular non‑quiesced snapshot operations finish without errors.
• The Windows guest VSS checks show the SQL Server VSS Writer (SqlServerWriter) in a failed state with an “Inconsistent shadow copy” error, matching the timing of the snapshot failures.
• The vssadmin list writers output further confirms problems with the SqlServerWriter component, as shown below:

  Writer name: 'SqlServerWriter'
     Writer Id: {a65f####-####-####-####-a0c4db26####}
     Writer Instance Id: {3090####-####-####-####-668c356e####}
     State: [11] Failed
     Last error: Inconsistent shadow copy

Environment

VMware vSphere ESXi

Cause

• The snapshot failures are caused by the SQL Server VSS Writer (SqlServerWriter) inside the Windows guest OS remaining in a Failed state with the error “Inconsistent shadow copy.” The failing component is the SQL Server VSS Writer (SqlServerWriter) within the guest OS VSS stack, not the VMware snapshot mechanism.
• When VSS‑based quiescing is requested, VMware Tools invokes the Windows VSS framework, which relies on all required VSS writers to be healthy. As SqlServerWriter has Failed, a consistent shadow copy set cannot be created, and the VSS request fails, causing the VMware quiesced snapshot operation to fail even though the ESXi and vCenter Server snapshot mechanisms are functioning correctly.

Resolution

Since the issue arises when one or more VSS writers are in a failed state, any problematic writers must be addressed at the application level. As VSS writers are supplied by third-party vendors, any issues/failures involving those writers should be addressed by engaging the respective vendor for troubleshooting and remediation.

Workaround:

1. Log in to the guest OS of the VM with administrative credentials.
2. Open the Run dialog, type services.msc, and press Enter to launch the Services console.
3. In the list of services, locate the SQL Server VSS Writer entry, right‑click it, and select Properties.
4. In the Startup type drop‑down, choose Disabled, click Apply, then OK, and ensure the service is stopped.
5. After this change, re‑test quiesced snapshot operations to confirm they complete successfully, bearing in mind that snapshots taken with the writer disabled are not fully application‑consistent.