Recovering data from LVM on RAID
I had two disks (2x250GB) with RAID1 (Linux software raid) on, and LVM on
top of this.
I was intending to replace this set with a set of 2x120 disks instead, and
using the 2x250 disks as in a LVM volume group
I started with setting up a new RAID1 with LVM on the 2x120 disks, pretty
straightforward. Then I broke up the 2x250 array, destroyed all partitions
on one of the disks, and made a new volume group and added this disk to it.
Then I copied roughly half of the data (the important data) over to the
volume group of the 2x120 RAID1. The other half went to the unimportant
volume group with the now just one 250GB disk. After this was done, and I
was pretty confident that all files had been copied (90% sure), I finally
removed the remaining bits of the 2x250 GB disk array, and destroyed all
partitions on the other 250 GB disk as well. I was about to add this as a
physical volume to LVM (pvcreate), but it would not let me (insisting that
the drive was busy, despite trying the usual tricks to "release" it). Ok,
so I rebooted, and pvcreate worked fine.
It is now that I discovered that roughly half of my "important" folders
were gone (in somewhat random order)! I was, as I said, 90% sure that I
had copied everything.
So here we are, at the core of the problem; how to recover the files?
If you have any experience in this field, or any pointers, suggestions
et.c. that can help me solve this problem, I would greatly appreciate it.
I have tried a few tools, the free linux recovery tool from r-tt.com, as
well as their full version (demo). I have also tried PhotoRecovery and
OnTracks EasyRecovery. These programs just leave me with thousands of
files, mostly with a "default extension", and some that the programs guess
are various files. When I look into the files, they also seldom start and
end where you would think (i.e. they contain fragments of XML/jpg and
other information...). R-tt's tool even suggested I had hundreds of ext2
partitions. I guess these results are logical consequences of using LVM,
since LVM works with PE's scattered around the disk.