Troubleshooting Volume Shadow Copy (VSS) quiesce related issues
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Troubleshooting Volume Shadow Copy (VSS) quiesce related issues

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Article ID: 344277

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Updated On:

Products

VMware vSphere ESXi

Issue/Introduction

Symptoms


Customers may experience failures when attempting to create quiesced snapshots of Windows virtual machines. In some cases, non-quiesced snapshots succeed, but quiesced snapshots fail during the VSS freeze phase. No snapshot delta files are created, and snapshot consolidation is not available.

 

  • When quiescing a guest operating system using the Microsoft Volume Shadow Copy Service (VSS) prior to a snapshot, the operation fails
  • You see one of these errors:
    • Cannot create a quiesced snapshot because the snapshot operation exceeded the time limit for holding off I/O in the frozen virtual machine
    • An error occurred while quiescing the virtual machine. The error code was: 4 The error was: Quiesce aborted
       
  • In the Event Viewer Application logs of the Windows Virtual Machine, you see errors similar to:
     
    • Event ID 11
    • Event ID 12292
    • Event ID 12032
    • Event ID 12298
       
  • The Event ID errors contain descriptions similar to:

    Volume Shadow Copy Service information: The COM Server with CLSID {<GUID>} and name <name> cannot be started. [<error code>].

 

These errors typically occur at the time the snapshot attempts to quiesce the guest operating system, indicating the failure occurs before snapshot creation completes.



Environment

VMware vSphere ESXi 6.x
VMware vSphere ESXi 7.x
VMware vSphere ESXi 8.x

Resolution

This issue is caused by failures within the Windows guest operating system’s Volume Shadow Copy Service (VSS) or associated VSS writers/providers. VMware snapshot functionality relies on VSS for quiesced snapshots, but does not control VSS behavior inside the guest OS.

Background Information

VMware products may require file systems within a guest operating system to be quiesced prior to a snapshot operation for the purposes of backup and data integrity.
 
VMware products which use quiesced snapshots include, but are not limited to, VMware Consolidated Backup and VMware Data Recovery.
 
As of ESX 3.5 Update 2, quiescing can be done by Microsoft Volume Shadow Copy Service (VSS), which is available in Windows Server 2003 and above versions.

Operating systems which do not have VSS make use of the SYNC driver for quiescing operations. When VSS is invoked, all VSS providers must be running. If there is an issue with any third-party providers or the VSS service itself, the snapshot operation may fail.
 
Before verifying a VSS quiescing issue, ensure that you are able to create a manual non-quiesced snapshot using the vSphere Snapshot Manager. For more information, see Troubleshooting issues when creating or committing snapshots in ESX/ESXi (1038963).
 

Troubleshooting Steps

Note: These steps may vary depending on the operating system.
 
  1. Ensure that all the appropriate services are running, and the startup types are listed correctly:

    Note: With the exception of the VMware Snapshot Provider service, all services listed below are Microsoft services bundled with the operating system. If you are having difficulty starting these services, consult Microsoft support before proceeding with the troubleshooting steps.
     
    • During the installation of VMware Tools (this is required to install the VMware Snapshot Provider Service):
       
      • Ensure that the COM+ System Application service is listed as started and that the startup type is listed as Manual.
      • Ensure that the COM+ Event System service is listed as started and that the startup type is listed as Automatic.
         
    • While Idle:
       
      • Ensure that the COM+ System Application is listed as started and that the startup type is listed as Manual.
      • Ensure that the COM+ Event System service is listed as started and that the startup type is listed as Automatic.
      • Ensure that the Volume Shadow Copy service is not running, and the startup type is listed as Manual.
      • The Microsoft Software Shadow Copy Provider service may or may not be started. Ensure that the startup type is listed as Manual.
      • Ensure that the VMware Snapshot Provider is not running and that the startup type is listed as Manual.
         
    • During the backup:
       
      • Ensure that the COM+ System Application is listed as started and that the startup type is listed as Manual.
      • Ensure that the COM+ Event System service is listed as started and that the startup type is listed as Automatic.
      • The Volume Shadow Copy service may or may not be started. Ensure that the startup type is listed as Manual.
      • Ensure that the Microsoft Software Shadow Copy Provider service startup type is listed as Manual.
      • Ensure that the VMware Snapshot Provider is listed as started and that the startup type is listed as Manual.
      • Ensure that the Virtual Disk is listed as started and that the startup type is listed as Manual.
      • Ensure that the Workstation is listed as started and that the startup type is listed as Manual.
         
  2. Make sure that you are using the Microsoft Software Shadow Copy provider:
     
    1. Click Start > Run.
    2. Type cmd and press Enter to open a command prompt.

      Note: You may need to run this as administrator.
       
    3. Check the VSS Providers with this command:

      C:\Users\Workstation> vssadmin list providers

      The output appears similar to this:

      Provider name: 'Microsoft Software Shadow Copy provider 1.0'
      Provider type: System
      Provider Id: {b5946137-7b9f-4925-af80-51abd60b20d5}
      Version: 1.0.0.7

      Check the permissions on the VSS and on any third party VSS providers and ensure that the account is valid. For more information, see the Microsoft Knowledge Base article 259733.

      If you have a third-party provider, it may interfere with the quiescing operation. Try uninstalling any third-party VSS providers.

      Note: The vssadmin utility and VSS are bundled with the Microsoft operating system. If the vssadmin utility is reporting errors, this may indicate that you may have a pre-existing issue with the VSS. Consult Microsoft support before proceeding with the next troubleshooting steps.
       
  3. Ensure that all the VSS writers are stable and that they are not reporting an error. Run this command:

    C:\Users\Workstation> vssadmin list writers

    The output for each writer appears similar to this:

    Writer name: 'VSS Metadata Store Writer'
    Writer Id: {75dfb225-e2e4-4d39-9ac9-ffaff65ddf06}
    Writer Instance Id: {088e7a7d-09a8-4cc6-a609-ad90e75ddc93}
    State: [1] Stable
    Last error: No error

    Ensure that the State is Stable and that the last line of the output is Last error: No error.

  4. If the issue persists, perform these troubleshooting steps:

    1. Run NTBackup and see if there are VSS errors when NTBackup attempts to run. 
    2. Try uninstalling/reinstalling VMware Tools to re-register VSS.
    3. If you are having difficulty backing up information from specific applications such as Microsoft Exchange, Microsoft SQL, and Active Directory, ensure that all necessary VSS writers are also installed with these components.
    4. Engage Microsoft support to ensure that there are no known issues with VSS. Visit http://support.microsoft.com/ to see if there are any patches and updates for VSS.
    5. Ensure that the time is accurate in the guest operating system and validate that it is being synchronized via NTP or VMware Tools.

Notes:

  • The Distributed Transaction Coordinator service must be running while installing VMware Tools. Otherwise, VSS fails to quiesce Windows 2008 R2/ Windows 2012.

Additional Information

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