ESXi: Snapshot management (storage locations)?

[maxi-m]

We are using the free licensed version of ESXi and are running low on local server storage - I would like to recover the local disk space used for Snapshot BU's and store them on a NFS Share on our SAN. I created the NFS volume and have access to it but don't see any way in ESXi to manage the Snapshot target location. Is V-Center the answer for this? I was looking on the VM site and it looks like the management pack must be purchased to run V-Center.

Also along the same line I understand that Snapshots can go stale - I've been doing weekly snapshots without the system memory to conserve disk space. What is the best solution to manage snapshots should there be a VM failure (can you recover an ESXi system form a snapshot?)

I'm slow at this so will appreciate any advice,

Mike

[weinstein5]

Be warned the ESXi snapshot is not a back up of the data - but in essence a transaction log of the changes made to the virtual disk since the time the snapshot was taken - so to back up the disk you would need both the original VMDK and the snapshot log - also it is not good practice to run production VMs with snapshots for too long in that as they grow larger they affect VM performance and fill up the disk -

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[maxi-m]

So the best solution is delete and recreate Snapshots for point in time

rollbacks - I'll need to re-read the section on Snapshots. I was

thinking that having a snapshot of the original image might be a way to

restore a lost VM -

MB

[hstagner]

Hello maxi-m,

To echo weinstein's previous statement, the snapshot mechanism is not a backup mechanism. Here is what happens when you take a vm snapshot.

-Initiate Snapshot

-A new file is created. This is the delta file that all changes to the vm disk is written to from the point of the snapshot forward.

-The original virtual hard disk of the vm is left intact and is not written to while the snapshot exists.

-When you delete a snapshot, the changes from the snapshot file are committed to the original virtual hard disk.

-If you revert back to a snapshot, the changes in the snapshot file are disregarded and you go back to the original virtual disk file (pre-snapshot).

To get a better understanding of all this, take a look at the VM's folder in the datastore browser when you take a snapshot (you will see the actual snapshot file *.vsp and it will grow over time)

So, to put all of this together, the reason you do not want to have VM's with snapshots for any long period of time is that the *.vsp file will grow very large over time, consuming your disk space. When you go to delete the snapshot, it will take a very long time to commit the changes or it may not work at all if you are running low on diskspace (the changes must be commited to the original *.vmdk before the snapshot file is deleted).

I hope this helps.

Don't forget to use the buttons on the side to award points if you found this useful (you'll get points too).

Regards,

Harley Stagner

[maxi-m]

Very good information... Thanks...

MB

[Texiwill]

Hello,

Moved to ESXi forum.

Best regards,
Edward L. Haletky
VMware Communities User Moderator, VMware vExpert 2009
====
Author of the book 'VMWare ESX Server in the Enterprise: Planning and Securing Virtualization Servers', Copyright 2008 Pearson Education.
Blue Gears and SearchVMware Pro Blogs -- Top Virtualization Security Links -- Virtualization Security Round Table Podcast

[jbroedel]

I would recommend to not keep the snapshots for long periods of time, regardless of size. I just had a scary moment when trying to delete one. It hung at 95% and I could not access the VM. It finally completed and all is well but it wasnt a fun experience.

There is a post that talks about this

http://communities.vmware.com/thread/73553