We have a server which we inherited from previous sysadmin. Now the RAID-5 (H/W based on IBM ServeRAID) now unusable, saying not enough disks to operate.
On ServeRAID Manager I can see three physical disks, and one logical volume. The logical volume properties says:
Data space: 698GB and Parity space: 232GB, from which I guess there should be four disks.
Am I right?
In the server there are three disks physically. (Each are 250GB disk.)
So now I should be sure the logical volume was built up originally from thee or four disks? How can be sure in it? I was unsure on proper meaning of Data space and Parity space in this terminology, if I have to sum them, it means four disks should have been there.
Just a guess shot, but after reading the question and 8 comments this seems possible... One of the disks have failed, but removed was not that one. Possibly the admin's mistake. If you can get the missing one there's some hope.
Does ServeRAID use DDF metadata? If so, it may be worth trying Linux
mdadm(ver. 3.0+) to re-assemble if hardware controller refuses to.