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micromacromonke
Contributor
Contributor

How 'safe' is consolidation of snapshot data? Backup ideas?

Hi all

(ESX 3.0.1)

Is consolidation of snapshot data a safe process? I have inherited a rather unfortunate situation:

An Exchange 2003/Win2003 guest with a 200GB data partition has 60 GB of snapshot files (multiple snapshots, 3 IIRC). There isn't a good backup of this server. There is a critical space situation on the LUN and we need that 60GB back, not to mention the fact that it is probably hitting server performance.

Can I guarantee (insofar as it is possible) that the snapshot consolidation process won't corrupt data? If not, what is the quickest way to make a complete recoverable backup of this server before I try, given that I have VCB and backupexec available, but not much free space on the LUN to play with (only 100GB). In addition I'm no ESX expert.

Is this process likely to take a while? I think I have around 4 hours of official out-of-hours time, does the consolidation need to be done while the guest is powered off?

thanks in advance for any replies!

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3 Replies
doctormiru
Enthusiast
Enthusiast

Hi

First of all I would take a backup of your Exchange DB (using ntbackup or similar online agents and save it outside the VM). Stop the Exchange Information store and delete the snapshots. Consolidating 60GB can take a while, depends on your storage infrastructure.

good luck

Michael

micromacromonke
Contributor
Contributor

Thanks for the reply, that's one option to consider. Smiley Happy

I spotted another thread on here where someone just cloned the guest to consolidate snapshots, but still with the ability to revert to the original if the clone process corrupted any data. I tried this on another server that was in a similar position, and it worked fine. However that server had a total of 70GB vmdk files after the clone was complete, and I had 150GB free on the LUN. Once I delete its old files I will have 200GB free. This is just enough space to fit a clone of the exchange server mentioned above, but does the cloning process require significant storage overhead for temp file storage etc?

Basically:

200 GB (nominal) guest plus 60GB snapshot files

just over 200 GB free space on the LUN

Is there space to clone this guest?

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kix1979
Immortal
Immortal

The snapshots will consolidate like this:

Snapshot 1 = 10G

Snapshot 2 = 5G

Snapshot 3 = 1G

When it consolidates it will be:

Snapshot 1 = 10G

Snapshot 2 = 6G

Snapshot 3 = Commited

Then is should do:

Snapshot 1 = 16G

Snapshot 2 = Commited

Finally it will commit the last snapshot to the underlying VMDK.

Also you could use VMBK, Ranger, esXpress etc... for a trial to backup the VM (all VMDKs and snapshots) then commit them. Worst case the VM dies on commital and you restore the whole VM back to VMFS and try again.

Thomas H. Bryant III
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