Solved

Is it possible to look/open a VMWare delta file

Posted on 2012-03-16
3
561 Views
Last Modified: 2012-03-17
We were having loads of issues with our SAN dropping connections and doing some really weird stuff so the decision was made to vmotion all disks to local storage, wipe the SAN and start again.

So thats what we did. Except now there are a few files/folders which are missing, and apparently not where they should be.

The only thing we can think of is that the fileserver had an unidentified 8GB delta (vmname-000001-delta.vmdk) left over in the SAN even after we'd migrated off.

We copied this off before wiping the SAN.

Is it possible our data is in this file? If so, how can we open it?

No backups either, they were failing all over the place becuase of the SAN issues.
0
Comment
Question by:hongedit
  • 2
3 Comments
 
LVL 119

Accepted Solution

by:
Andrew Hancock (VMware vExpert / EE MVE^2) earned 500 total points
ID: 37730747
This is the Snapshot Delta file, your data will be in this file, but you need to have the Parent Disk to the Child Snapshot file, to merge before you can check the data.

If you only have the Delta disk - No.


A snapshot is NOT a backup of a VM; that is a gross misconception.  

A snap shot is a way to preserve a point in time when the VM was running OK before making changes. A snapshot is NOT a way to get a static copy of a VM before making changes.  When you take a snapshot of a VM what happens is that a delta file gets created and the original VMDK file gets converted to a Read-Only file.  There is an active link between the original VMDK file and the new delta file.  Anything that gets written to the VM actually gets written to the delta file.   The correct way to use a snapshot is when you want to make some change to a VM like adding a new app or a patch; something that might damage the guest OS. After you apply the patch or make the change and it’s stable, you should really go into snapshot manager and delete the snapshot which will commit the changes to the original VM, delete the snap, and make the VMDK file RW. The official stance is that you really shouldn’t have more than one snap at a time and that you should not leave them out there for long periods of time. Adding more snaps and leaving them there a long time degrades the performance of the VM.  If the patch or whatever goes badly or for some reason you need to get back to the original unmodified VM, that’s possible as well.  

I highly recommend reading these 2 articles on VMware Virtual Machine Snapshots:

Understanding Snapshots - http://kb.vmware.com/kb/1015180
Snaphot Best Practices - http://kb.vmware.com/kb/1025279

Also check out the following Snapshot Articles by Eric Siebert

Pt.1- http://is.gd/Lajg4p
Pt.2- http://is.gd/NdKQWC
Pt.3- http://is.gd/tp2vEK
0
 
LVL 1

Author Comment

by:hongedit
ID: 37732413
I know about snapshots, and we weren't knowing running any - I learnt the hard way before.

The only reason a snapshot would be there is I think, due to a failed veeam backup.

I've been reading it is possible to recover data from just a delta file but it requires indepth knowledge about the old base disk which is now gone, and even then its a specialist job - I dont think the data is worth that much, as we have restored a semi-recent verswion of it.
0
 
LVL 119

Assisted Solution

by:Andrew Hancock (VMware vExpert / EE MVE^2)
Andrew Hancock (VMware vExpert / EE MVE^2) earned 500 total points
ID: 37733167
If you do not have the parent disk, you would need to use a company like Kroll Ontrack.
0

Featured Post

PRTG Network Monitor: Intuitive Network Monitoring

Network Monitoring is essential to ensure that computer systems and network devices are running. Use PRTG to monitor LANs, servers, websites, applications and devices, bandwidth, virtual environments, remote systems, IoT, and many more. PRTG is easy to set up & use.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

When converting a physical machine to a virtual machine using VMware vCenter Converter Standalone or vCenter Converter Enterprise, if an adapter type is not selected during the initial customization the resulting virtual machine may contain an IDE d…
In this step by step tutorial with screenshots, we will show you HOW TO: Enable SSH Remote Access on a VMware vSphere Hypervisor 6.5 (ESXi 6.5). This is important if you need to enable SSH remote access for additional troubleshooting of the ESXi hos…
This tutorial will walk an individual through the steps necessary to configure their installation of BackupExec 2012 to use network shared disk space. Verify that the path to the shared storage is valid and that data can be written to that location:…
This tutorial will walk an individual through locating and launching the BEUtility application to properly change the service account username and\or password in situation where it may be necessary or where the password has been inadvertently change…

805 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question