Is it safe to delete this snapshot?

vmware-esxi snapshot

10,774

Deleting a snapshot can cause a performance impact to your storage layer, especially if there's a lot of writes to the guest during the process. If you can do it when it's powered off, there's no writes at all, obviously, so do that.

Regarding space : "From ESX4.0 Update 2 onwards, the snapshot mechanism has changed. VMware ESX now incorporates improved consolidation procedures which lessen the demand of free space. You are able to consolidate virtual machine delta disks even while minimal free space on your datastore is available."

http://kb.vmware.com/selfservice/documentLinkInt.do?micrositeID=&popup=true&languageId=&externalID=1015180

10,774

Author by

DKNUCKLES

Penetration Tester / InfoSec Consultant, OSCP / OSCE, educator to anyone wanting to keep their information safe. Always be learning.

Updated on September 18, 2022

Comments

DKNUCKLES over 1 year

Building on a previous question I had asked re: a VM freezing at the end of the backup, one of the solutions Veeam has offered is to make sure that there are no other snapshots that exist of that vm. After looking into it, I've found the following snapshot (presumably from a borked backup job)

I would like to delete this snapshot in hopes of resolving my issue, however I need to ensure that the machine isn't negatively affected by this. Reading the VMWare documentation on the issue it states :

Deleting a snapshot leaves the current state of the virtual machine or any other snapshot untouched. Deleting a snapshot consolidates the changes between snapshots and previous disk states and writes to the parent disk all data from the delta disk that contains the information about the deleted snapshot. When you delete the base parent snapshot, all changes merge with the base virtual machine disk.

Below is a picture of the datastore of the virtual machine (Datastore is DAS). If I schedule downtime for this server and shut it off during the process, can I safely delete this snapshot without any negative ramifications on the machine? I need to ensure that the state of the machine stays exactly how it is.

EDIT : For anyone interested this snapshot was successfully deleted last night without turning the machine off. It took about an hour and a half to consolidate the snapshot. After the snapshot was deleted, both snapshots mentioned by Jeff Hengesbach are no longer there.
- Danila Ladner almost 11 years
  
  How do you think deleting this snapshot will affect your VM after you've read an official VmWare statement? What are the fears still?
- DKNUCKLES almost 11 years
  
  Well for starters the size of the snapshot (and only 77GB is available on the datastore) - I don't know if the size of the snapshot will cause an adverse reaction
- Danila Ladner almost 11 years
  
  Oh, yeah you need to make sure your datastore has more free space than provisioned space for that VM. Good point.
- DKNUCKLES almost 11 years
  
  In this case it doesn't however - a consultant did a P2V conversion for me a while ago and over-provisioned the machine. Hence my concern
- Danila Ladner almost 11 years
  
  Then you can't delete it. You need to expand your datastore first.
- mfinni almost 11 years
  
  The "needing equal space" issue used to be a thing (worst case) in old versions of ESX 4.0 and previous. Not on 5.0, which your other post says you're running. See my edited answer.
- mfinni almost 11 years
  
  @DanilaLadner - see my answer.
- Jeff Hengesbach almost 11 years
  
  Interesting the GUI is showing one snapshot, but ds browser shows there are two - 00001 and 00002 files. More so is the 00002 is much older. Previous snapshot issues?
Danila Ladner almost 11 years

Id o not think it applies for thin provisioned VMs.
mfinni almost 11 years

Please read the article I linked. It doesn't even mention thin provisioning, which has nothing to do with what we're talking about.
Danila Ladner almost 11 years

Right, sorry about that one it has nothing to do with that, my fault. I had the ticket open in this regard and they strongly recommended to have enough free datastore space to cover provisioned VM space to remove snapshot. And the ticket was open when I ran ESXi 5.0 Did you remove personally sizable snapshot on provisioned 500G VM with Datastore free space 50G?
mfinni almost 11 years

Here's a good description of the old behavior compared to the current behavior : yellow-bricks.com/2010/07/05/…
mfinni almost 11 years

The base disk may grow somewhat if thin-provisioned, yes - and if DKNUCKLES has over-committed his disk, then that's a potential problem, and not only one related to snapshots.