Can’t rebuild RAID 5 Array

3wareraidraid5

In a previous message I have asked how to rebuild a faulty disk in a RAID 5 array with 4 disks.
I have mounted a new drive (drive 4) in place of the faulty one and started a rebuild.
During the rebuild, another disk (drive 2) started throwing ECC errors and timeouts. AT 95% of the rebuild process, the computer rebooted and hang at the start screen, with the controller (3ware 9500s) showing an error (drive 2 not found) and a typical noise coming from the faulty drive (drive 2), could be heard.
I have turned off & on the PC few times, no changes.
Then I have left the PC off for an hour. Turned on again, his time the missing drive (drive 2) was back in place. I could bot the operating system awaiting for the rebuild, started automatically from the controller.
At a certain point, the controller started gave a rebuild error and halted the rebuild process. The server is now running with drive 2 with errors and drive 4 with a OK status, but degraded as the rebuild process could not complete.
It looks like I'm at a dead end: at least 3 drives need to be ok to make things good, however one drive has errors and one drive is not rebuild..
What can I try?

Best Answer

Your best bet is to restore from backups. But I'm guessing you don't have those, or you wouldn't be asking the question.

So, failing backups, your next best bet is to copy as much of the data off as possible (from the sounds of things you'll have at least a couple unreadable sectors that won't be copyable) with whatever method you favor - file copy, disk image, disk-level copy, etc. Then once you have your data, you can replace the faulty drives, create a new RAID array and copy your data back.

Failing that, you can go through the expensive process of professional data recovery or just accepting your data loss and moving on, depending on how much your data is worth to you.