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Disable VSS application quiescing using VMware Tools

  • 20 January 2022
  • 6 replies
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Userlevel 2
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  • Commvault Certified Expert
  • 21 replies

Hi, 

If a VM has the setting to Disable VSS application quiescing in VMware Tools, will this affect the VADP initiated quiescing through CV VSA backup? 

Will it at all affect the Filesystem and Application Consistent (quiesced) data protection operation?

/Patrik 

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Best answer by Aplynx 21 January 2022, 16:04

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6 replies

Userlevel 6
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Hi @Patrik,

We are reliant on VMware to perform the Quiesced Snapshot, So it will depend on the result from VMware.
Note that is a Quiesced Snap fails, we will request a standard Snapshot and use that for the backup.

Have you tried a Quiesced Snapshot of the VM in VMware? - What is the result?


Also, what’s the reasons for disabling App Quiescing here?
-You can disable specific writers as per VMware article here.
 

Best Regards,

Michael

 

Userlevel 6
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On the CommVault side if the subclient is set to crash consistent it doesn’t request a quiesced snapshot and this is the type it will default to if quiescing fails.

Userlevel 2
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Thanks guys, 

I am aware of the VSA quiesce function initiated from a CV backup. In this case this is a setting done when using IBM Sepctrum Protect as the Windows applications got issues during the backup. In these cases with the CV backup I just configured a separate subclient for crash consistent backups and thats it. 

When I run backups on Windows VMs the job does not complains about being unable to quiesce the VM so it seems as it has no affect.   

The question here is if the setting in vm-tools in any way affects the CV backup or if that setting is for something else completely and maybe even ignored. If it has an affect it would be interesting to know what that is and if I should recommend the customer to remove it. 

Hope this make my question/concern a bit clearer :-) 

/Patrik

Userlevel 6
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The request to VMware to create a snapshot with the quiescing option is a pass\fail. If the snapshot comes back and vmware says its quiesced commvault moves on, if it fails then a request for a non-quiesced snapshot is made. So long as you can create quiesced snapshots in vmware when commvault requests vmware to create the same there shouldn’t be an issue.

Userlevel 2
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So during an FS & Application consistent backup there is no integration with vmtools and VSS during the VADP initiated quiesce? Basically the vmtool setting to disable application quiesce is overridden by the VMware VADP-initiated, quiesced backup? 

And the initial reason for the setting in vmware tools (quiesce-issues for the application) may happen again? 

Userlevel 6
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CommVault makes an API request to VMware and VMware says pass\fail on the snapshot being quiesced. If it’s successful we keep it, if not we request a non-quiesced. All interactions are done in VMware.