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I lost all of my data (8 TB) which I collected over the past few years yesterday because I made some seriuos mistakes during the remounting of my LVM. I run a XenServer5.6 installation with additional 4 harddisks for data storage. An LVM over those 4 HDDs was used to store all of my data. Yesterday, I reinstalled XenServer and wanted to mount my old Harddrives and add the LVM. I run

xe sr-create [...]

for all disks (/dev/sdb .. /dev/sde), but that was totally wrong. This command deletes the old LVM on the disks and created an new, empty lvm on every single disk with no partitions. No i got 4 empty harddrives :(

Is it possible to recover some data from that lost LVM volumes? I have no clue how to do it because i deleted all informations about the old LVM. Is there a way to access the files insed that old lvm directly?

Matthias Bayer
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1 Answers1

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Try vgcfgrestore. LVM normally saves backup of all LVM metadata in /etc/lvm/backup and older backups go in /etc/lvm/archive.

To check what backups you have:

vgcfgrestore -l <volumegroupname>

A dry run of a backup restore:

vgcfgrestore -t <volumegroupname>

And actually restore the most recent backup:

vgcfgrestore <volumegroupname>

To restore a different backup (check the output of the -l switch):

vgcfgrestore -f /etc/lvm/archive.... <volumegroupname>
chutz
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  • Thanks for your answer! When are those backups created? The only command I executed was the "xe sr-create.." command, does this create such an backup? – Matthias Bayer Dec 07 '12 at 12:16
  • A backup is created every time you run a command to modify the LVM. So a backup would have been created every time you modify your `lvm` configuration with `lvcreate`, `lvremove`, etc. Or even `vgs`. – chutz Dec 07 '12 at 16:39
  • Oh no, there was no backup :( Just one for the XenServer installation lvm... damn! I'll try to read raw data somehow next... – Matthias Bayer Dec 07 '12 at 20:31
  • You can search for file system superblocks using certain tools. For example, when recovering from a lost disklabel in a BSD system, you can run scan_ffs(8) to discover data about file systems on a given disk. There should be similar tools for Linux and instructions for recovering the data. – Bort Dec 12 '12 at 21:04