RAID5 - 2 drives have failed, can I recover?

[markdw77]

Dear all,

I have a RAID 5 configuration with 6 hard drives. 2 of these hard drives (drive 0 and drive 4) have both failed. When I boot I get "operating system not found" message, I am (was) runnung NT4.

Can anyone advise how I can recover from this problem?

 

[AberdeenTech]

Unfortunately a RAID 5 array can only sustain the failure of a single drive. In the event that two drives actually fail the volume will no longer be accessible. It is always possible however that the drives have not actually failed and have just gone offline for whatever reason. I have seen this happen with just about every type of RAID controller but LSI is most famous for kicking drives offline. A good way to see for sure whether or not your drives have actually failed is to test the drives using disk diagnostic utilities available from all hard drive manufacturers. These tests are non-destructive and will tell you for sure if there is indeed a physical problem with the drive. If after testing you find that no defects are found you should try powering down the server and reseating the drives and/or cables. Sometime it is that simple especially with SATA drives. If that doesn't work you can enter into the RAID controller Bios upon reboot and try to put the drives back online. You should download the latest user manaual for you RAID controller which will show you how to do this.

 

[markdw77]

Hi and many thanks for your reply.

I am pretty sure we are dealing with a hardware faliure, the primay drive in the array produces a nasty clicking and whirring noise, as if it is trying to spin up but not getting very far (sounds a bit like a dodgy cd trying to be read).
I think the best I can do is send the server off to hospital to be looked at by someone with experience of data recovery.

Any reccomendaions anyone? I am in London.

Many thanks