Hello,

I spent a night trying out mdadm --assemble on a virtual machine to
see how it attempts to fix a raid where 2 or more drives have been
marked faulty.
I was quite sure that the drives were fine and that they were wrongly
marked as bad.
I think I just have a bad ata controller.

I used --assemble on real machine and it seemed to have detected the raid again.
1 drive was found to be bad and it is recreating it now.
But my data is there and I can open it.
I am going to get some dvd's and back all this up before it dies again!


Regards and thanks for your help!


2009/1/30 David Greaves [off-list ref]:

Justin Piszcz wrote:

quoted

Try to assmeble the array with --force.

hmmmm? not yet...

quoted

On Thu, 29 Jan 2009, Tom wrote:

quoted

Hello,

2 drives have failed on my raid5 setup and I need to recover the data
on the raid.
I am sure that the drives still works or at least one of them still
works.

How do I recover my drives?

How important is it?
The more important the data the more you should reduce the risk of a subsequent
failure.
If you "don't care" then we just force it back together and cross fingers.
Otherwise we run tests on all the drives before trying a restore.
I'd say to run these tests on each drive; as a minimum do the first test on the
failed drive, more paranoia, more tests and include the non-failed drives (to
ensure they don't fail during recovery):
* smartctl -t short
* smartctl -t long
* badblocks

What happened? Smoke?
Are the drives faulty (what does smartctl -a tell you)
Did the cables just wiggle? Is the controller broken?
You probably don't know :)

I would obtain replacements for the failed drives and use ddrescue to copy from
the failed drive to a replacement.
Then install the good drives and begin recovery.

quoted

quoted

I can't mount the raid no more and I am missing a hard drive when i
run ls /dev/sd?
I have 7 drives on my raid.

You say you have 7 drives and 2 are failed.
And yet I see 4 drives, not 5.

Where is sdg?

quoted

quoted

Here is output of /var/log/messages in following link

http://matx.pastebin.com/m35423452

Jan 29 21:14:11  sda died
Jan 29 21:14:12  sdb died

quoted

quoted

also some more information

Also need:
 Distro
 Kernel version
 Mdadm version
 mdadm --examine for each available component.

David

--
"Don't worry, you'll be fine; I saw it work in a cartoon once..."