[ale] File recovery

Ed Cashin ecashin at noserose.net
Mon Jan 6 10:29:02 EST 2014


Well, if you're lucky enough that the new install is smaller than the
old one, and the VM disk images happened to be past the point that the
new install wrote on the disk, and if you're lucky enough for the VM
images to be physically contiguous on the disk (thick provisioning
would probably make that the case), then you could scan for the magic
number of the VMware image in the block device itself and find the
beginnings of the images.  There's probably some metadata in the disk
image header that will tell you the size to copy out to a new file.

Yes, Googling for VMware disk image magic found PDFs that have details
about reading the metadata.  I don't know if this link
(http://www.vmware.com/app/vmdk/?src=vmdk) will work for you, but the
vmdk_specs.pdf says,

  magicNumber is initialized with

  #define SPARSE_MAGICNUMBER 0x564d444b /* 'V' 'M' 'D' 'K' */

... and it has info on interpreting that particular version of the
disk image format.

Good luck.


On Sun, Jan 5, 2014 at 3:46 PM, Beddingfield, Allen <allen at ua.edu> wrote:
> Oh, ouch.  If it zapped all the partitions and installed over, I don't think there is going to be any way to recover.
>
> --
> Allen Beddingfield
> Systems Engineer
> The University of Alabama
> ________________________________
> From: ale-bounces at ale.org [ale-bounces at ale.org] on behalf of Jim Kinney [jim.kinney at gmail.com]
> Sent: Sunday, January 05, 2014 2:35 PM
> To: Atlanta User Group (E-mail)
> Subject: Re: [ale] File recovery
>
>
> VM were not on backup. Local snapshots were on disk. Supposed to be demo and testbed stuff but apparently not all was disposable.
>
> On Jan 5, 2014 2:51 PM, "Beddingfield, Allen" <allen at ua.edu<mailto:allen at ua.edu>> wrote:
> What type of backups do you have? Whole VM backups or file level? I assume they were on a datastore on local disk?
>
>
> From: Jim Kinney [mailto:jim.kinney at gmail.com<mailto:jim.kinney at gmail.com>]
> Sent: Sunday, January 05, 2014 01:12 PM Central Standard Time
> To: Atlanta User Group (E-mail) <ale at ale.org<mailto:ale at ale.org>>
> Subject: [ale] File recovery
>
>
> Haven't had to do this in a while so I'm looking for ideas.
>
> VMware ESX host rebooted. The bios was set to pxeboot. The pxeboot process it picked up installed Fedora19 over the ESX.
>
> sigh
>
> Looking for recommendations for tool chains for VM recovery. I'm not expecting much success but trying to balance reconstruct time vs recovery time.
>
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-- 
  Ed Cashin <ecashin at noserose.net>
  http://noserose.net/e/
  http://www.coraid.com/


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