MDADM Raid5 Failure

[dade49]

Please help.

I don't understand what happened. I lost over 600GB of data on my 1TB Raid 5 array. Here are the specs:

Debian 3.1
2x 36GB sata drives raid1
6x 200GB sata drives raid5
using mdadm for raid

My raid1 array is fine. The system boots, but cannot start /dev/md2 which is my raid5 array. It gives an error about the superblock being the wrong size. Am I totally screwed?

I tried to run the array manually by typing:
mdadm --run /dev/md2
This gives the message:
mdadm: failed to run array /dev/md2: Invalid argument

Someone please help me. I'd say I'm an intermediate user of linux/Debian, but am new to mdadm. Thanx.

[jwilliams]

Well, I have no idea how to help, but I just wanted to say...
"That sucks, and I feel for you."

600GB is a serious loss.

Keep the hope, though!

[paradigm]

If ever you have a RAID that doesn't mount and is inaccessible, the first thing you always do is image the entire system.
You do this by running this command in a shell:
dd if=/dev/md1 of=/recoverymount/md1.image bs=512 conv=noerror,sync

Run this when you have mounted a large external drive onto your system that can store the space of your drive (i.e. in your case 600GB).

After you have an image of your failed partition, you can run a number of filesystem recovery or diagnostic programs over it.
A while ago, I had a critical 10GB Mirrored RAID partition go on a business server because of a UPS failure. It killed the partition on the RAID which meant I had to restore from backups and recover data from the partition image.

To recover a Linux filesystem or files I normal use R-Linux.

If you're new to RAID, know this:
RAID will NOT protect you from all Hardware, Software or Human Errors or Failures.
Because of this, you must have a separate server or drive for all your backups and data. Don't put all your trust in RAID.
RAID when setup in a mirrored configuration will protect you from Hard Drive failure, but not much else.

Best regards,
David