please help. RAID 5 crashed after power failure. How do I recover the data?

[SoftDux]

Hi all

I hope someone can help me with this. The posts in the forum on similar topics didn't help me at all. I just move aprox. 280GB's worth of data to a new server, which has 3x250GB HDD's in. The 4th drive had a problem and was sent back to supplier, so I would have added it later.

Anyway, this morning we had a power failure (UPS also faulty :( ), and now the server doesn't start-up. It seems like /dev/md1 is fine, but /dev/md2 isn't.

Here's the output that I can currently see on the monitor:


RAID 5 conf printout:
--- rd:3 wd:2 fd:1
disk 0, o:1, dev:hdb2
disk 2, o:1, dev:sdb2
raid5: failed to tun raid set md2
md: peers->run() failed ...
mdamd: failed to RUN_ARRAY /dev/md2: Invalid argument
Making device-mapper control mode
Scanning logical volumes
Reading all physical volumes. This may take a while ...
cdrom: open failed.
No volume groups found
Activating logical volumes
cdrom: open failed
Volume group "main" not found
ERROR: /bin/lvm exited adnormally! (pid 485)
Creating root device
Mounting root filesystem
mount: error 6 mounting ext3
mount: error 2 mounting none
Switching to new root
switchroot: mount failed: 22
umount /initrd/dev failed: 2
Kernel panic - not syninc: Attempted to kill init!


Booting from the CD, and specifying "sme rescue" wasn't very helpful, as it tells me there's no installation found. So, I can't even try and rebuild a failed RAID: http://wiki.contribs.org/Raid#Raid_Notes


I have booted up with System rescue CD, and found some interesting info:


sysresccd ~ # fdisk -ul

Disk /dev/sda: 250.0 GB, 250058268160 bytes
255 heads, 63 sectors/track, 30401 cylinders, total 488395055 sectors
Units = sectors of 1 * 512 = 512 bytes

Device Boot Start End Blocks Id System
/dev/sda1 * 63 208844 104391 fd Linux raid autodetect
/dev/sda2 208845 488392064 244091610 fd Linux raid autodetect

Disk /dev/sdb: 250.0 GB, 250058268160 bytes
255 heads, 63 sectors/track, 30401 cylinders, total 488395055 sectors
Units = sectors of 1 * 512 = 512 bytes

Device Boot Start End Blocks Id System
/dev/sdb1 * 63 208844 104391 fd Linux raid autodetect
/dev/sdb2 208845 488392064 244091610 fd Linux raid autodetect

Disk /dev/sdc: 250.0 GB, 250059350016 bytes
255 heads, 63 sectors/track, 30401 cylinders, total 488397168 sectors
Units = sectors of 1 * 512 = 512 bytes

Device Boot Start End Blocks Id System
/dev/sdc1 * 63 208844 104391 fd Linux raid autodetect
/dev/sdc2 208845 488392064 244091610 fd Linux raid autodetect



One thing which I don't understand though, is that it detects all 3 HDD's as sdX, even though I have 1x IDE & 2x SATA HDD's in the server.

Can someone please give me some pointers on this?

[topdog]

You seem to have a double problem, i think you are running lvm on top of raid that is usually difficult to rescue.

You need to try and fix the raid array this should help

mdadm --assemble --run --force --update=summaries /dev/md2
/dev/disk1 /dev/disk2 /dev/disk3


Replace with your actual setup.

Going through "man mdadm" should help.

[unclecameron]

Also you may have luck mounting Knoppix and attempting to mount the device and fsck it, which if it's decent at all you should see on the desktop when you power it on. HTH

[SoftDux]

Thanx, I tried Sysrescue CD, which is also a live CD and similar to knoppix, but with more tools - unfortunately it didn't help much. I'm still looking into option though...