Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people, just like you, are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
Solved

How can I recover a zero byte avhd file that should be several hundred gigabytes?

Posted on 2014-08-02
1
288 Views
Last Modified: 2014-09-09
I have a SAN in operation with two LUN(s) and one of those luns is 9 terabytes.  This LUN is mounted via two nodes within a Hyper-V Cluster using a cluster shared volume.  Recently I discovered that a virtual machine failed and looking at the cluster shared volume ("C:\ClusterStorage\vmroot") I saw that the AVHD file (most recent snapshot) that should be several hundred gigabytes is now a 0 byte file.  It has become corrupt or something else has happened to it.  

     I unmounted that volume and that particular LUN is no longer being written to and no data has been written to C:\ClusterStorage\vmroot.  After copying the initial 0 byte avhd file to a remote share I opened the file in WinHex which revealed not much info at all.  It appears that the header isn't correct, however windows (2008 R2) does correctly show the filename.  It seems to me that the actual data should still be there on that LUN which happens to be a 6 disk raid 5 LUN.  

Does anyone have an idea on how to properly retrieve this data or is it even possible?
0
Comment
Question by:linuxrox
1 Comment
 
LVL 119

Accepted Solution

by:
Andrew Hancock (VMware vExpert / EE MVE^2) earned 500 total points
ID: 40236584
I know you do not want to hear this, but snapshots (AVHD) should never be able to run for more than 48 hours.

Microsoft does not support a VM, which is running on a snapshot for more than 48 hours, performance will be poor, and there is the chance of corruption.

Back to your issue, 0 byte Snapshot (AVHD) file, the data has been lost. So all data since the snapshot has been created has been lost, which could be many days, if you believe the snapshot should have gigs.

I would be inclined now to congtact a Data Recovery Specalist, such as Kroll Ontrack for Recovery.

There are not the cheapest, but can recover from these situations, if the data is important and you do not have a backup to restore.

http://www.krollontrack.co.uk/

To understand Hyper-V Snapshots further consult this article

Hyper-V Snapshots FAQ
0

Featured Post

NFR key for Veeam Backup for Microsoft Office 365

Veeam is happy to provide a free NFR license (for 1 year, up to 10 users). This license allows for the non‑production use of Veeam Backup for Microsoft Office 365 in your home lab without any feature limitations.

Question has a verified solution.

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

Suggested Solutions

Title # Comments Views Activity
"Error while attempting to connect to View Composer" 4 311
Virtual Machine Consolidation needed status 6 126
Unable to remove VSphere from Host Machine 5 49
Hypervisor 1 U 10 36
It Is not possible to enable LLDP in vSwitch(at least is not supported by VMware), so in this article we will enable this, and also go trough how to enabled CDP and how to get this information in vSwitches and also in vDS.
Exchange server is not supported in any cloud-hosted platform (other than Azure with Azure Premium Storage).
This tutorial will walk an individual through configuring a drive on a Windows Server 2008 to perform shadow copies in order to quickly recover deleted files and folders. Click on Start and then select Computer to view the available drives on the se…
This tutorial will walk an individual through setting the global and backup job media overwrite and protection periods in Backup Exec 2012. Log onto the Backup Exec Central Administration Server. Examine the services. If all or most of them are stop…

860 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