[CentOS] Re: Hellllp Pl: Centos 4.4 Default LVM install boot/recovery problem

Wed Mar 21 19:38:08 UTC 2007
Sanjay Arora <sanjay.k.arora at gmail.com>

On Wed, 2007-03-21 at 08:42 +0530, Sanjay Arora wrote:
> Hello all
> Nill experience with LVM. Have a Default Centos 4.4 install updated till
> a week ago with three HDDs. System's not booting up since my staff
> pulled out the plug due to a short circuit nearby. 
> Machine is a PIII 550 MHz, with 3 HDDs 40 GB, 120 GB (Actually is bigger
> but my bios detects only upto 120 GB) & 20 GB...about half filled with
> data & the backup server taken out in the short circuit.
> Upon bootup, the system starts with root, kernel & initrd notices, then
> says Uncompressing Linux then spits out the Error....CRC Error -- System
> Halted.
> Booted from the CD in reinstall mode where anaconda looks for linux
> installations on the HDD and asks about upgrade, reinstall or fresh
> partition/create partition/delete partition for reinstall, but the
> installer does not detect any linux installation on the HDD. I aborted
> at that stage.
> Now my system is a default linux installation where I have used the
> autopartitioning done by the system (LVM2) and almost all of my data is
> either in /home directory or couple of directories in the /
> I am willing to do a reinstall if my data is preserved. What do I need
> to do to diagnose the problem? and pointers to recovering from this
> problem and various tradeoffs. Can't lose data, as already have lost
> backup server (smps, motherboard, hdd circuitry all short-circuited, so
> no hope there). LVM howto was not much of a help as it seems to mostly
> have how to expand or reduce lvm and similar issues.
> Please keep in mind that I am a user and not sys-admin, though I can use
> command-line, if instructions & how-tos are there.
> Please help.
> With best regards and thanks in anticipation.
> Sanjay.
> If LVM volume was spread across all the drives, and one drive is damaged, you
> will have a hard time recovering the data. It can be done, but it will be
> difficult. Do you have a better idea of how the data was laid out?
> If there was electrical problems, you might have damage to this system also.
I don't think there is any physical damage to these HDDs, as the system
boots & acceses the boot partition & gets CRC error on reading some
data...maybe lvm data.

And yes, the lvm volume would be spread across all the HDDs. So how do I
find out lvm configuration data and give it to lvm? or maybe there is a
way to mount lvm slices one by one and copy the data to a fourth HDD?

With regards & thanks for taking the time to respond.