[CentOS] Recover lost data from LVM RAID1

Fri Jan 18 20:23:43 UTC 2008
William L. Maltby <CentOS4Bill at triad.rr.com>

On Fri, 2008-01-18 at 15:01 -0500, Alain Reguera Delgado wrote:
> Guys,
> 
> The other day while working on my old workstation it get frozen and
> after reboot I lost almost all data unexpectedly.
> 
> I have a RAID1 configuration with LVM. 2 IDE HDDs.
> 
> md0 .. store /boot (100MB)
> --------------------------
> /dev/hda2
> /dev/hdd1
> 
> md1 .. store / (26GB)
> /dev/hda3
> /dev/hdd2
> 
> The only info that still rest in was that, that I restore after the
> fresh install. It seems that the disk were with problems and weren't
> syncing :(. I confessed, I didn't check that at first time but after I
> lost the data and check /var/log/messages I saw that.
> 
> >From /var/log/messages
> ...
> Jan 17 12:22:15 zion kernel: md: raid1 personality registered for level 1
> Jan 17 12:22:15 zion kernel: device-mapper: ioctl: 4.11.0-ioctl
> (2006-09-14) initialised: dm-devel at redhat.com
> Jan 17 12:22:15 zion kernel: md: Autodetecting RAID arrays.
> Jan 17 12:22:15 zion kernel: md: invalid raid superblock magic on hda3
> Jan 17 12:22:15 zion kernel: md: hda3 has invalid sb, not importing!
> Jan 17 12:22:15 zion kernel: md: autorun ...
> Jan 17 12:22:15 zion kernel: md: considering hdd2 ...
> Jan 17 12:22:15 zion kernel: md:  adding hdd2 ...
> Jan 17 12:22:15 zion kernel: md: hdd1 has different UUID to hdd2
> Jan 17 12:22:15 zion kernel: md: hda2 has different UUID to hdd2
> Jan 17 12:22:15 zion kernel: md: created md1
> Jan 17 12:22:15 zion kernel: md: bind<hdd2>
> Jan 17 12:22:15 zion kernel: md: running: <hdd2>
> Jan 17 12:22:15 zion mcstransd: mcstransd starting
> Jan 17 12:22:15 zion kernel: raid1: raid set md1 active with 1 out of 2 mirrors
> Jan 17 12:22:15 zion kernel: md: considering hdd1 ...
> Jan 17 12:22:15 zion kernel: md:  adding hdd1 ...
> Jan 17 12:22:15 zion kernel: md:  adding hda2 ...
> Jan 17 12:22:15 zion kernel: md: created md0
> Jan 17 12:22:15 zion kernel: md: bind<hda2>
> Jan 17 12:22:15 zion kernel: md: bind<hdd1>
> Jan 17 12:22:15 zion kernel: md: running: <hdd1><hda2>
> Jan 17 12:22:15 zion kernel: md: kicking non-fresh hdd1 from array!
> Jan 17 12:22:15 zion kernel: md: unbind<hdd1>
> Jan 17 12:22:15 zion kernel: md: export_rdev(hdd1)
> Jan 17 12:22:15 zion kernel: raid1: raid set md0 active with 1 out of 2 mirrors
> Jan 17 12:22:15 zion kernel: md: ... autorun DONE.
> ...
> 
> This computer is really old, Celeron 800MHz, 256MB of RAM and IDE disk too.
> 
> I know that I have to suffer the consequences but if you know some way
> to recover some data, help me please.
> 
> These days I have been reading about: mdamd, and some way to recover
> but no success:
> 
> I tried to boot from rescue mode with CentOS 5 first CD and do an fsck
> to /dev/hda3 and /dev/hdd2. After this something about superblock was
> told to me and that use the command e2fsck -b 8123 <device> (I don't
> remember the number exactly) but no success either.
> 
> Do you have some idea ?

I've not used raid, but your file system is inside LVM, from what you
say. You need to have LVM active and fsck on /dev/<your logical vol> for
fsck to work.


> 
> Thanks guys,
> 
> Cheers,
> al.
> <snip sig stuff>

HTH
-- 
Bill