Linux LVM on MD raid problem with recovery

How to use TestDisk to recover lost partition
Message
Author
mcc666
Posts: 3
Joined: 18 Jul 2012, 22:59

Linux LVM on MD raid problem with recovery

#1 Postby mcc666 » 18 Jul 2012, 23:16

Hello,

due to unknown reason my md based raid5 on 3 drives got corrupted. one drive just went out from the group (and in fact was showing all ok when i was trying --examine it). So I removed all partitions from that drive (as i couldn't re-enable or re-add it to the md group) and just re-added to md group using mdadm. Unfortunately during rebuilding my PC just stopped responding. I had to reset it. After that i couldn't even start my raid with 2 working previously disks, so i decided to recreate the md structure. Mdadm discovered that these two discs (which were ok) are part of the same group, so i formed up raid 5 with 2 partitions only, and then added corrupted one. All got rebuild, but i lost my lvm structure which was on top of md (one vg + a few lvgs). All standard tools coming with lvm were not showing any info about lvm groups on my md.

I was trying to use TestDisk 6.13 to see if i can find any sign of LVM on my recreated md volume. I took option none for partition type, but see some strange results - only HFS and FAT12 (I don't know what it could be), but no LVM information. Am I proceeding correctly and it means i lost all data (a few 100s MB very important)? Or there is other way i should try?

Thanks in advance for any help.

Best regards,
MCC

Sponsored links

mcc666
Posts: 3
Joined: 18 Jul 2012, 22:59

Re: Linux LVM on MD raid problem with recovery

#2 Postby mcc666 » 19 Jul 2012, 12:21

I spotted that during discovery there are two lines LVM, but at the end these are neither on the list of non-recoverable partitions nor on the list of partitions to be recovered.

Is there any way to recover LVM? What settings shall i use?

Best regards,
MCC

mcc666
Posts: 3
Joined: 18 Jul 2012, 22:59

Re: Linux LVM on MD raid problem with recovery

#3 Postby mcc666 » 23 Jul 2012, 22:37

I found something strange - windows version of testdisk tool seems to "see" more than linuks one:

1. Windows does not see my md raid5 (sees 3 separate disks), but can see and tries to recover my lvm2
2. Linux version sees md raid5, during partition scanning sees lvm2, but at the end is not proposing to revcover it.

And here comes my questions:

1. is it possible to "force" the tool somehow to see lvm2 under linux?
or
2. is it possible to force the tool somehow to see underling md raid 5 under windows?

Thanks for any help!

Best regards,
MCC


Return to “Partition Recovery”

Who is online

Users browsing this forum: Yahoo [Bot] and 0 guests