Removing Snapshots

[JustyC]

Question on snapshots.... We powered off a group of W2K8 guests and took snapshots.  A few days later our developers asked us to put the guests back to the point in time when the snapshots

were taken.   In snapshot manager we clicked on Go To, had the developers check to ensure their changes were not present.  All appeared to be good, but later we noticed the original snapshot

entries still show in snapshot manager.  We were thinking the Go To option put the guest back to the state the guest was in at snap time and removed the snap file.  Apparently not.  We no longer

need the snapshot file(s).  Can we just select Delete All,  which would leave the guests functioning the way they are now and also delete the snap file ?

[MKguy · Accepted solution]

Can we just select Delete All,  which would leave the guests functioning the way they are now and also delete the snap file ?

Yes. Deleting snapshots is non-disruptive to the VMs and will transfer the changes of the delta files into the VMs base disks.

When you create a snapshot, you basically create a delta file for each virtual hard disk. All future write IOs will go to this file. When you select "go to" you are reverting a snapshot to that point in time it was created, meaning the current delta file with the changes since that point is discarded and a new, empty one is created for recording all future changes.

See this article for more details:

VMware KB: Understanding virtual machine snapshots in VMware ESXi and ESX

[a_p_]

Can we just select Delete All,  which would leave the guests functioning the way they are now and also delete the snap file ?

Yes.

Reverting to a snapshot only resets/clears the snapshot file, but doesn't physically delete it. To get rid of the snapshot files you need to run "Delete" or "Delete All". Running "Delete All" in the current state will merge the changes (after the GoTo) to the base disk, i.e. preserve the current state.

André