Bad VMDK File / Crashed System

Posted on 2011-09-02
Last Modified: 2012-05-12
I had a Server 2008 virtual machine running on an ESXi host.  Users were reporting that file access from it was very slow.  I looked around a bit, and found that the file size at the datastore level was much higher than what it should have been for that server (compared it wish another ESXI host that has the exact same specs, and  a similar guest OS, and the size of the one in question was almost double.  I ran a checkdsk on the guest OK, and then ran Disk Defragmenter.  The datastore had been reporting about 30 Gigs free at the beginning of the process (as compared to the one that's working okay, with about 200 free), but after a bit of time the server froze up.  I checked the datastore, and there was only a few megs left of free space.  

I was able to delete an old host that I no longer needed, and freed up some space.  I left the guest turned off, and tried to add the VMDK file as a hard drive for another virtual server that was running fine.  It came up and said it was unformatted and asked if I wanted to format it.  I clicked cancel.  In computer management, it showed up as a FAT file instead of NTFS.

I disassociated it from that machine, and associated it back with the original one.  Now when I try to boot I get a message saying that there's no OS, use recovery disk, etc.  When I put the Windows Server disk in and boot to that, chose the recovery option, get to the dos prompt, and go to the drive and type "Dir" nothing shows up.

I can just rebuild the machine, and probably could have done that in the time it took me to compose this message, but the problem is that the guest o/s is a Domain Controller, and I'd really like to be able to recover it instead of having to remove it from the domain manually and readding it.

Thanks for any suggestions on how to recover the VMDK.
Question by:GMC02108
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LVL 121
ID: 36474920
What you describe, seems to suggest that the virtual machine, disk had a snapshot associated with it, would explain, the reason for the increase in disk size, and increase when you started to defragement the disk, and when the datastore was full, the VM would stop.

Also a VM in Snapshot mode is slow.

Did the virtual machine, or have you been using VM Snapshots on the virtual machine?

As for recovery, forget for the moment, that it is a virtual machine and it's a VMDK, the Recovery Process is exactly the same as for a physical machine.

But have you been using snapshots, or have any error messages about the disk?

Author Comment

ID: 36475032
There are a couple of other VMDK files with 0001, 00002 at the end.  There was a snapshot from last January, but I collapsed that yesterday afternoon while I was searching for when I was trying to figure out why the machine was going so slow.  Is there a utility I can run on the VMDK to try and fix it?
LVL 121
ID: 36475289
There is no utility to fix VMDKs.

You'll need to try a recovery at the VM OS.

Those files usually indicate a snapshot - "maybe" present.

Are they still present, did the snapshot get removed successfully, how long was the VM in snapshot mode?

It's possible that the snapshot, not being closed correctly, has caused the corruption of the virtual disk.
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Author Comment

ID: 36475524
When I click on snapshots it says that there aren't any present.  When I deleted it, there was an error message that popped up at the end, but I can't find it in the event log to tell you what it said.  
LVL 121

Accepted Solution

Andrew Hancock (VMware vExpert / EE MVE^2) earned 500 total points
ID: 36475810
Okay, so your issue, seems to have started with a Snapshot deletion issue, and hence why the Virtual Machine disk is corrupted.

I think it's unlikely that any recovery process is going to be able to recover or fix the corruption, without a means to merge the snapshots correctly, there will be an issue with the main virtual disk.

Try a Windows 2008 Recovery/Repair from the DVD. But I fear the damage may not be repairable.

Author Closing Comment

ID: 36554791
There was no fix, other than rebuilding the server.

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