Re: DP 6.20 - Restore of VMWare Guest Does Not Restore OS (1640 Views)
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Michael Filippidis
Posts: 32
Registered: ‎02-26-2008
Message 1 of 4 (1,702 Views)
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DP 6.20 - Restore of VMWare Guest Does Not Restore OS

Hi All,

 

I am testing the VMWare Granular Recovery agent and have managed to backup and restore an individual file to a guest VM after a long and protracted process.

 

I am now trying to test restoring a whole guest VM to cover the scenario where a guest VM becomes unstable/unbootable/corrupted etc.

 

I went through the procedure of restoring the guest VM from within the DP GUI > Restore > Virtual Environments interface and nominated the option to restore to the orginal datacenter etc and to delete any existing matching VM before the restore.  I also specified that the restore task should register the guest VM and restart it.

 

The task completed and I then used the GRE File Browser option to try and restore all the files back as I could not see any other way to simply restore the guest VM in total.

 

But when I then checked the guest VM Console view in my VSphere client I could see that the no OS could be found for the guest VM.  So it is possible that the last step was a mistake on my part but I honewstly could not see how to select a restore of the entire guest VM (not a single file recovery) after the initial restore from backup tape to the Mount Proxy.

 

I then tried to restore the guest VM to a different directory (the Mount Proxy disk on the backup host).  When that task finished, I could see four files created: a .vmd file, a flat file, a META file for the scsi disk object and an .xml file with a long GUID-like string for a name.  However, no .vmxf file which my VMWare admin advises is required in order to try and manually restore the guest VM from the files on the Mount Proxy using a tool like VMWare Converter.

 

If anyone is able to suggest why VMWare is now not able to find an OS for the guest VM or what the correct workflow is for restoring a guest VM in total I would be grateful.  All the documentation I have read seems to gloss over the scenario of restoring an entre guest and the discrete steps invlved in that in favour of the more granular recovery scenario.

 

Kind Regards,

 

Michael

Honored Contributor
Sebastian.Koehler
Posts: 1,157
Registered: ‎02-27-2007
Message 2 of 4 (1,654 Views)

Re: DP 6.20 - Restore of VMWare Guest Does Not Restore OS

Please make sure you apply the latest patches for Data Protector 6.20, including the patch bundle to 6.21 or start over with version 7.0 to avoid patching. Make sure you select the whole VM for backup and exclude only drives you want to skip. (not the other way around) The restore of a complete VM does not involve the GRE plugin. This should be done using the Data Protector GUI.

Regards,
Sebastian
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Advisor
Michael Filippidis
Posts: 32
Registered: ‎02-26-2008
Message 3 of 4 (1,650 Views)

Re: DP 6.20 - Restore of VMWare Guest Does Not Restore OS

Hi Sebastian,

 

The issue was fixed by ensuring that the VMWare datastore disk that is also presented to the backup host is in "Online" mode within the backup hopst's Storage Management applet.

 

After rebuilding the test guest VM and performing a fresh backup and ensuring the datastore disk was set to "online" in the Windows OS of the backup host the restore of the entire guest VM worked.

 

In our environment, we have explicitly set the Automount option to disabled on the backup host being used for VMWare integrated backups/restores so that any VMWare datastores that are presented to it for this purpose do not get corrupted by the backup host trying to write a signature to the disk or otherwise attempting to mount it as soon as it finds the disk.  Appparently, however, simply setting the datastore disk to "online" mode does not do any of these things so the datastore is not corrupted but is now actually accessable for the restore to function.

 

To quote the information that was sent to me from my HP contact:

 

"The issue has its root cause from the API. Here´s the entry from vSphere 5.0 U1 VDDK Release notes * VDDK fails to returns error for SAN writes to offline or read-only LUN. When attempting SAN transport writes to virtual disk on an offline or read-only LUN, VDDK 5.0 writes appear to succeed despite the LUN being offline or read-only. Specifically, VixDiskLib_Open() returns success because of accessible LUN, but VixDiskLib_Write() does not return an error even though it cannot write to an offline or read-only LUN. For backup and restore software running through a proxy, this issue causes restores to return success, although nothing is actually written to virtual disk. When a LUN is offline, write and write operations should return an error. When a LUN is read-only, write operations should return an error. See KB 2010428.  (VMware Knowledge Base article)"

 

Regards,

 

Michael

Honored Contributor
Sebastian.Koehler
Posts: 1,157
Registered: ‎02-27-2007
Message 4 of 4 (1,640 Views)

Re: DP 6.20 - Restore of VMWare Guest Does Not Restore OS

Ok, got that. In times of VCB, offline stores where a good idea while with VEPA this works like a charm. There is also an omnirc option to perform restores using NBD, in case the datastores are presented only read only. This will also work around that issue, if you need to keep the datastores offline. Please mark this topic as resolved, if you have no further questions.

 

Regards,

Sebastian

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