Configuring application consistent quiescing for Windows VMs
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Configuring application consistent quiescing for Windows VMs

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Article ID: 303299

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Updated On:

Products

VMware vSphere ESXi

Issue/Introduction

Windows VMs may fail to quiesce snapshots.
Similar errors to the following may be observed in the following log locations:

  • vmware.log
'VssSyncStart' operation failed: Operation aborted (0x80004004) warning"
YYYY-MM-DDTHH:MM:SS [FFA18B90 verbose 'PropertyProvider' opID=CA0E7426-00005219-58] RecordOp ASSIGN: info.error, task-142530
YYYY-MM-DDTHH:MM:SS [FFA18B90 info 'Default' opID=######26-0000####-58] [VpxLRO] -- FINISH task-142530 -- -- vpxapi.VpxaService.createSnapshot -- 5229b79e-ce92-3d72-81e9-c22f5ec4923d
YYYY-MM-DDTHH:MM:SS [FFA18B90 info 'Default' opID=######26-0000####-58] [VpxLRO] -- ERROR task-142530 -- -- vpxapi.VpxaService.createSnapshot: vim.fault.ApplicationQuiesceFault:
 Error when notifying the sync provider
Quiesce operation aborted
[msg.snapshot.quiesce.vmerr] The guest OS has reported an error during quiescing
  • %windir%\temp\vmware-vmss.log
YYYY-MM-DDTHH:MM:SS.mmmZ In(05) vmx - [msg.snapshot.quiesce.vmerr] The guest OS has reported an error during quiescing. 
YYYY-MM-DDTHH:MM:SS.mmmZ In(05)+ vmx - The error code was: 3 
YYYY-MM-DDTHH:MM:SS.mmmZ In(05)+ vmx - The error message was: Quiesce operation canceled 
YYYY-MM-DDTHH:MM:SS.mmmZ In(05) vmx - ToolsBackup: changing quiesce state: FINISHING -> ERROR_WAIT 
YYYY-MM-DDTHH:MM:SS.mmmZ In(05) vmx - ToolsBackup: changing quiesce state: ERROR_WAIT -> IDLE 
YYYY-MM-DDTHH:MM:SS.mmmZ In(05) vmx - Vix: [mainDispatch.c:4211]: VMAutomation_ReportPowerOpFinished: statevar=3, newAppState=1880, success=1 additionalError=0 
YYYY-MM-DDTHH:MM:SS.mmmZ In(05) vcpu-0 - Vix: [mainDispatch.c:4211]: VMAutomation_ReportPowerOpFinished: statevar=3, newAppState=1881, success=1 additionalError=0 
YYYY-MM-DDTHH:MM:SS.mmmZ In(05) vmx - GuestRpc: Got error for channel 0 connection #####: Remote disconnected

 

Environment

VMware ESXi 7.x
VMware ESXi 8.x
VMware ESXi 9.x
Windows VMs utilizing OS or Application level shadow copy operations

Cause

These errors are consistent with the missing advanced VM value - disk.EnableUUID

VMware uses a hardware snapshot provider to perform application-level quiescing within Windows VMs. 
Setting the advanced virtual machine parameter disk.EnableUUID to true is necessary for application-consistent quiescing, as it allows the VM to provide the guest OS with the UUID (Universally Unique Identifier) of each virtual disk.

This allows the Volume Shadow Copy Service (VSS) and various application writers to correctly identify which disk corresponds to which volume, ensuring that data is properly flushed and writers can generate necessary metadata files (such as writer.xml).

Resolution

To enable Windows virtual machine application-consistent quiescing:

  1. Open the VMware vSphere Client, log in to vCenter Server
  2. Locate the virtual machine in question, and power off the virtual machine
  3. Right-click the virtual machine, choose Edit Settings
  4. Click VM Options tab, and select Advanced
  5. Click Edit Configuration in Configuration Parameters
  6. Click Add parameter
  7. In the Key column, type disk.EnableUUID
  8. In the Value column, type true
  9. Click OK and click Save
  10. Power on the virtual machine

To disable application-consistent quiescing, replace "true" with "false" in step 8. 

To disable application quiescing without virtual machine downtime, use the following steps to update the vmware tools configuration within the VM:

  1. Open C:\ProgramData\VMware\VMware Tools\Tools.conf file using a text editor. If the file does not exist, create it.
  2. Add the following lines:

    [vmbackup]
    vss.disableAppQuiescing = true
     
  3. Save and close the Tools.conf file
  4. Restart the VMware Tools Service for the changes to take effect:
    # Restarting of the VMware Tools Service does not reliably stop the vmtoolsd.exe process. Use the following instructions to completely stop and start the service. 
    1. Click Start > Run, type services.msc, and click OK
    2. Right-click the VMware Tools Service and click Stop
    3. Open Task Manager. In the Processes tab, search for vmtoolsd.exe
    4. Right-click on vmtoolsd.exe and stop the process
    5. In guest guest OS Services window,  right-click the VMware Tools Service and click Start.
    6. Ensure that the vmtoolsd.exe service has restarted in the Processes tab.
      Note: In some versions of VMware Tools, this service is named as VMware Tools Service(VMTools)
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