Guest Processing - application-aware image processing

[kurt]

I have a backup job which backs up 11 virtual machines. Three of those virtual machines are running sql server.

Should I enable Application-aware image processing for the entire backup job? I was going to do that then go to advanced and disable it for all the servers except the ones running sql server. Does this make sense or should I have a separate backup job for sql servers?

Also, in Advanced section there is indexing which is set to partial. Do I need to disable this? I did not select "Enable guest file system indexing" so I'm not sure why it appears to be enabled in the advanced options.

[Gostev]

Generally speaking, you want to enable application-aware image processing for each Windows VM starting from XP and later, because it particularly enables application-level quiescence for backup snapshot. My Windows 7 desktop has 11 VSS writers, and they are there for a good reason... so, not using this option puts as many as 11 applications or services at risk even on Windows desktop, and needless to say there will be even more VSS-enabled applications on servers.

If you use Advanced settings section to configure certain VMs separately, then the settings there take precedence over settings in the wizard, so yes, you want to disable it if needed.

[kurt]

Thanks for the info. I will try enabling it for all my Windows VM's. I also noticed that there is another option called "Enable VMware tools quiescence" Does this also need to be enabled?

[Gostev]

No, you do not need to enable this (and in all cases, it will be ignored if you enable application-aware image processing in Veeam, as they are not compatible). This option is primarily used for OS other than Windows, where you need to be using VMware prefreeze and postthaw scriptps to quiesce OS and applications properly.

[Daveyd]

What if an non VSS aware application like MYSQL is installed on a Windows VM? Would application-aware image processing on that VM be useful?

[Vitaliy S.]

In this case you should be using VMware prefreeze and postthaw scripts to have application consistent backups.

[kurt]

Thank you. I have enabled "Enable application-aware image processing" on all my windows machines. Will this increase backup time? If this is highly recommended then it seems like it should be enabled by default. It's also a bit confusing that file system indexing is enabled if I use the advanced settings even though I don't have it enabled in the guest processing screen.

[Vitaliy S.]

Will this increase backup time?

The time difference will not be noticeable.

[kurt]

Just curious but what would happen if I tried to restore a Windows virtual machine running MSSQL server and "application-aware image processing" was disabled?

This question is not Veeam related. If I create a snapshot of a MSSQL server using vsphere client, then revert to the snapshot, would it work? Does that invoke the vss writers?

[Gostev]

Assuming you are using vSphere 4.1 or later, if you chose "Quiesce guest" option when creating a snapshot, then it will invoke VSS writers, and both snapshot and rollback will work fine. Unlike Active Directory DC or Exchange, Microsoft SQL does not require application-specific restore steps, and is smart enough to understand it is being restored off VSS backup.

Even without guest quiescence, generally speaking most databases can recover from crash-consistent state without any issues. They are just built and polished with this use case in mind (power loss should not result in data loss).

One thing that can hurt Microsoft SQL very bad is the SYNC driver that was used to quiesce guest file system in earlier VMware version. By all means, stay away from it, because with high SQL load it is very likely to causes sever issues to your SQL VM.

[derekf]

But as I understand it quiesce guest does not seem to work on Windows Server 2008 R2 which causes problems when you want to use this to backup VMs where you can't enable application aware image processing (if you can't get any access or credentials for a guest OS), What's the best option then?

[Gostev]

Crash-consistent backups is the only option in this case.

[cindermonkey]

Having only Guest Processing \ Enable guest file system indexing selected (Enable applicaton-aware image processing is NOT selected) on an Exchange 2003 VM, I still have the option to truncate the Exchange Transaction Logs in the Advanced Options. Is this fine or is it contradicting the description for enabling application aware image processing "performs transaction logs processing" as this option is not able to be selected because it interferes with Inmage replication (vss writers become unstable)

Thanks!

[Gostev]

If the application-aware image processing is disabled, log truncation will not happen in any case. The options you are looking at control log truncation behavior for when application-aware image processing is enabled.