CentOS - Oct 2006 - Help request...recovering LVM on centos 4.2

I installed a Centos 4.x system using a lvm install across four HDDs.
It is my first install using LVM. System had a power-failure and
stopped booting up. A new trainee simply took out the HDDs and
restarted the file-server on a fresh HDDs.

Now the problemis that the four HDDs have data. But the order of the
HDDs (of install....1st primary, 2nd primary etc.) is unknown. Earlier
we used to boot with knoppix live cd and recover data through rsync.
Knoppix is not automatically recognizing lvm partitions.

My query is to ask for step by step instructions on finding & mounting
my lvm partitions correctly using knoppix or installing earlier hdds
one by one in the new file-server & restoring data to users. Pointers
on any howtos or detailed examples of recovery would also be
appreciated.

With best regards.
Sanjay.

Sanjay Arora spake the following on 10/24/2006 3:21 PM:
> I installed a Centos 4.x system using a lvm install across four HDDs.
> It is my first install using LVM. System had a power-failure and
> stopped booting up. A new trainee simply took out the HDDs and
> restarted the file-server on a fresh HDDs.
> 
> Now the problemis that the four HDDs have data. But the order of the
> HDDs (of install....1st primary, 2nd primary etc.) is unknown. Earlier
> we used to boot with knoppix live cd and recover data through rsync.
> Knoppix is not automatically recognizing lvm partitions.
> 
> My query is to ask for step by step instructions on finding & mounting
> my lvm partitions correctly using knoppix or installing earlier hdds
> one by one in the new file-server & restoring data to users. Pointers
> on any howtos or detailed examples of recovery would also be
> appreciated.
> 
> With best regards.
> Sanjay.
I think LVM should be able to find the data through its metafiles. You
probably have some corruption that killed it in the first place. That is one
of LVM's failings.
Knoppix will not automatically mount LVM, but you should be able to boot in
rescue mode from your centos cd. The easiest way to see what drive was which
would be to look at the drives set as master. One will have 2 partitions, and
the other will have one. The one with 2 partitions is the primary master.
The slaves will be a crapshoot if you aren't sure, but LVM should be able to
mount them if they aren't corrupt.
I haven't seen any foolproof rescue disks for LVM yet, but look for
something
with EVMS on it. I think systemrescuecd  http://www.sysresccd.org/Main_Page
might help you, but don't hold me to it. You might try something like this
http://aplawrence.com/Linux/lvm.html
next time for a little more safety.

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