I have a Dell 2600 with 6 drives configured in a RAID 5 on a PERC 4 controller. 2 drives failed at the same time, and according to what I know a RAID 5 is recoverable if 1 drive fails. I'm not sure if the fact I had six drives in the array might save my skin.
I bought 2 new drives and plugged them in but no rebuild happened as I expected. Can anyone shed some light?
Best Answer
Regardless of how many drives are in use, a RAID 5 array only allows for recovery in the event that just one disk at a time fails.
What 3molo says is a fair point but even so, not quite correct I think - if two disks in a RAID5 array fail at the exact same time then a hot spare won't help, because a hot spare replaces one of the failed disks and rebuilds the array without any intervention, and a rebuild isn't possible if more than one disk fails.
For now, I am sorry to say that your options for recovering this data are going to involve restoring a backup.
For the future you may want to consider one of the more robust forms of RAID (not sure what options a PERC4 supports) such as RAID 6 or a nested RAID array. Once you get above a certain amount of disks in an array you reach the point where the chance that more than one of them can fail before a replacement is installed and rebuilt becomes unacceptably high.