What is the best practice to remove a large Snapshot?

[bestview]

We have a Virtual Machine with 6 snapshots that was created by veeam that couldn't be removed autmatically (we didn't recognize that till lately). The partition is 1.5 TB and the oldest snapshot is 1TB.

I removed one of the latest Snapshot (~30GB) ant this took about 2 hours and used about 300GB on the Disk.

On the disk 800GB are free and im a bit affraid to remove the large snapshot because it is 1TB in size.

The version of vmware is 6.7 and there are 3 Servers and one HP MSA Storage.

Has someone experience how much space such a snapshot removal is using?

Is it better to remove all snapshots at once or remove step by step from the newest?

Or are there any other tips how to remove this snapshot?

TIA

Rolf

[Alex_Romeo]

Hi,

• https://interworks.com/blog/ijahanshahi/2013/06/20/vmware-performing-safe-removal-large-snapshots
• VMware Knowledge Base
• Recommended way to remove a VM Snapshot?

ARomeo

[NathanosBlightc]

Has someone experience how much space such a snapshot removal is using?

When you take a snapshot from a virtual machine, the operation will create a parent/child hierarchy of virtual disks (*.VMDK files) and also related information for snapshot database (*.VMSD file) and because of that, any further disk operation will happen on this new delta disk. So whenever you want to remove on of the snapshot, the host will consolidate the child disk's data into the parent, so it needs enough free space on the datastore at least equal of the delta disk. (It will merge them into a single VMDK). I think it's not bad to check out my post and also its attached references about the VMware snapshot mechanism and know how it really works in detail:

Virtual Machine Snapshot Details Investigation - Part 1

Is it better to remove all snapshots at once or remove step by step from the newest?

Safest and easier way to do, while sometimes maybe it's the faster way, instead of removing all of the snapshots from the parent one.

[a_p_]

Whether the snapshots can safely be deleted mainly depends on how the VM's virtual disks have been provisioned, and whether it's done with the VM powered on, or off.

In case of thick provisioned virtual disks, snapshots can be deleted (using "Delete All", and the VM bring powered off) with almost no requirement for additional free disk space.

Deleting the snapshots while the VM is powered on, or if thin provisioned virtual disks are used, will require temporary disk space, where the amount depends on different things.

If you want, then run ls -lisa > filelist.txt from the command line to list all of the VM's files, and attach the "filelist.txt" to your next reply. This will then respond with possible options.

André