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Admiral Huddy
09-02-2009, 10:40
First time for me..

I have a screen showing that RAID-5 has failed. Continuing the startup process I then get a black screen stating "disk read error".

The system won't boot.

Being RAID-5, I would have thought this would have just downgraded to a single disk config, reporting the disk in error?

My questions are:

1. How can I determine which disk is in error?
2. How can I recover from this?

Any help would be greatly appreciated.

Thanks
Daz
09-02-2009, 10:47
RAID-5 must be at least 3 disks, if you're down to a single disk then you're buggered.

The RAID controller software/BIOS will tell you which disk has failed - first thing remove that disk and try a boot with the degraded 2 disk array.
Admiral Huddy
09-02-2009, 11:01
Thanks Daz, That's the point, It just says RAID 5 has a status of FAILED during post but doesn't say which disk.

Then it continues to say "disk read error" with no clue as to what has failed. It's going to be pretty unlikely that 2 disk have failed. I'm wondering if it's the parity disk that's failed.

??
Daz
09-02-2009, 11:09
There will be some sort of key combination to get into the controller BIOS - it should spit out that combination when the controller posts (CTRL+A, CTRL+D - could be anything). You need to get into the controller to see what's going on.
LeperousDust
09-02-2009, 11:33
Thanks Daz, That's the point, It just says RAID 5 has a status of FAILED during post but doesn't say which disk.

Then it continues to say "disk read error" with no clue as to what has failed. It's going to be pretty unlikely that 2 disk have failed. I'm wondering if it's the parity disk that's failed.

??

RAID5 doesn't have a parity disk, it interleaves parity throughout. Press something like F5/F11 etc... before your computer even tries to boot from a hard drive.
Admiral Huddy
09-02-2009, 11:40
Edit - ok you ar correct..

http://www.easeus.com/resource/raid5.htm
Mark
09-02-2009, 11:59
Yup, as Daz said, try things like Ctrl+A, Ctrl+D, etc. This is the one big reason why RAID is not a backup solution. :(
Admiral Huddy
09-02-2009, 12:58
The chap has backups thanksfully.

Ok, I'm going to run the Samsung HDD check on each of the drives later today. Assuming I find the faulty drive, it should be a case of just replacement and the system will correct itself, right?
Dr. Z
09-02-2009, 13:05
Depends on the controller. You *need* to get into the controller's menu (assuming its a proper RAID card and not a windows fakeraid arrangement) and see what the score is.

Do you know what model of card it is? It is SCSI/SAS yeah?
Admiral Huddy
09-02-2009, 13:09
It's just an onboard ICH9R controller.
Dr. Z
09-02-2009, 13:13
Ah. Not a real RAID card then. I assume the array was the boot volume then? No Windows = no RAID utilities usually. I've got to scoot off to work now but I'm sure someone else here can help you out, if not I'll be back later and see if I can help you out :)