Urgent: XenServer 6 and issue with Virtual Disk

[wesleyw]

I have a VM that will not start if you attach the VM disk to another vm then it will not start so it's not difficult to work out that the VM disk is corrupted in some way. Is there anyway of fixing a VM disk or getting data from it as they've recently inputted loads of data and the backup isn't scheduled daily or weekly for this?

 

 

 

Help!

 

Thanks,

 

Wes

[twin--turbo]

can you try adding it as the second "Non Boot" disk. Not sure if it will work.

 

Rob

[Willott]

What's your backend storage? Looking at our backend storage, the disks are VHD files, so it's potential you could copy it off or export through xencenter and try to attach in Windows 7 Creating, Attaching, and Mounting VHD Files in Windows 7 and Windows 2008 R2 :: Windows 7 :: Articles & Tutorials :: WindowsNetworking.com

 

Cheers

 

Will

[wesleyw]

Running on iSCSI Dell PowerEdge SAN MD3600

 

I'll have to have a look at our backend to see what they are stored as.

[wesleyw]

Sadly stored as LVM any ideas for that storage format?

 

 

Wes

[Willott]

try export with Xencenter? (right click on shut down VM and do export)?

[dhicks]

Sadly stored as LVM any ideas for that storage format?

 

XenServer uses LVM to chop your storage up into block devices, so each LVM partition is useable as a Linux block device (i.e. a harddrive). XenServer uses the first LVM partition on the volume as a metadata store - it simply writes a wodge of XML data straight to the LVM partition, no filesystem or anything. This metadata can be corrupted - if you use an ampersand in the name of a virtual machine, for instance, the XML parser seems to choke. The solution I've found in the past was to simply reformat the matadata partition - XenServer will simply rescan the volume and recreate a new metadata block. Google for details before you actually do this, though.

 

If the disk's file system is corrupt but the disk itself is mountable then you might be able to repair it by attaching it to a virtual machine and booting whatever repair CD you want - the Windows install CD if it's a Windows server, I guess.