snapshot removal concerns

[aiea96701]

I have a customer who has been using snapshots for backups.  Many VMs have nested snapshots that have extended over months.   He is running out of DataStore space and I have suggested that we could reclaim much of the space by removing snapshots.   His concern is that by removing the snapshots that the VMs will shutdown.   I want to cover my bases before I contact him.  I am certain that under normal conditions the removal of a snapshot will not harm the VM but will take a tremendously long time to be removed.   Is there any way to expedite removal of snapshots ?   Is there any way that I can assure him or can make certain that no adverse issues will exist when removing snapshots from a live VM?

[Troy_Clavell]

....I want to cover my bases before I contact him.  I am certain that  under normal conditions the removal of a snapshot will not harm the VM  but will take a tremendously long time to be removed.   Is there any way  to expedite removal of snapshots ?   Is there any way that I can assure  him or can make certain that no adverse issues will exist when removing  snapshots from a live VM?

Depending on how deep the snapshot tree is, and the size of the snapshot, you could have some issues with Disk I/0 on the guest, which could appear to the end use the guest is down.  What I would suggest is to commit the snapshots after hours, where you are least likely to cause disruptions.

Also, if you can afford the downtime, and easy way to commit the snapshots is to use VMware Converter.

Also, confirm you have enough free space on the LUN to commit these snapshots.

[jasoncllsystems]

Please DO NOT use snapshot as a backup.

I have a bad experience with snapshot and normally I would try not to keep any snapshot for more than 2 weeks.

[a_p_]

I have a customer who has been using snapshots for backups

You should really talk to your customer about a real backup solution!

About the snapshots: What is the exact version/build of ESX(i) he is running! This is important for the way you can commit the snapshots. If he is running ESX(i) 4.0 prior to Update 2, DON'T use the "Delete All" function, this will most likely fill up the datastore.

Deleting the snapshots using a one-by-one strategy might be a good way, if you have to do it while the VM's are up and running. Always "Delete" the snapshot closest to the base disk in the snapshot manager.

André

[aiea96701]

Troy,

if a snapshot file is 4gb....will that commit require an additional 4gb on the LUN?   What if he does not have the capacity to commit the snapshot already, what other options do I have for him?

[jasoncllsystems]

Storage vMotion to another bigger LUN.

[Troy_Clavell · Accepted solution]

if a snapshot file is 4gb....will that commit require an additional 4gb on the LUN?

yes.

What if he does not have the capacity to commit the snapshot already, what other options do I have for him?

then, power off the guest, use VMware Converter, which will commit all the snapshots.  When the V2V is done, power on the "clone" confirm, then delete the original from disk.

[aiea96701]

Thanks again.  thought that would be the answer....he's pretty adamant about not downing the VMs but with his situation, he may not have a choice since his DataStores are already very, very low in capacity.   What I'll try to do is work with the smaller VM snapshots first before the larger

[a_p_]

Troy Clavell wrote:

if a snapshot file is 4gb....will that commit require an additional 4gb on the LUN?

yes.

Sorry, but I do not agree with you here 100%. It depends...

If the VM's virtual disk is thick provisioned and you delete the snapshot closest to the base disk, then you don't need additional disk space, since the snapshot data is committed directly to already allocated base vmdk. Only when committing the last remaining snapshot you may need some disk space for a consolidate helper snapshot which might temporarily be created.

André

[Troy_Clavell]

Sorry, but I do not agree with you here 100%. It depends...

You are correct, and I should have clarified my reply with a little more details besides "yes".

[aiea96701]

didn't think you could sVMotion a disk with snapshots