In a four drive configurations the disks are designated as /dev/sda3, /dev/sdb3, /dev/sdc3 and /dev/sdd3. To see the status of a disk, run the following command:
mdadm –examine /dev/sdX3 (note two dashes before examine) (where X is the specific disk you want to see: a, b, c or d).
A typical response from a rebuilding system is:
Magic : a92b4efc
Version : 00.90.00
UUID : deb59104:76824796:23cdfde1:5cc09783 <- UUID significance explained below
Creation Time : Wed Feb 10 15:04:08 2010
Raid Level : raid5
Used Dev Size : 976759936 (931.51 GiB 1000.20 GB)
Array Size : 2930279808 (2794.53 GiB 3000.61 GB)
Raid Devices : 4
Total Devices : 4
Preferred Minor : 1
Note: Check if all working disks have identical UUID after issuing this command on all disks.
I believe that your disks will not have identical UUIDs indicating a failed array.
The operating system partition is md0. Data is on md1. See the Intel® Entry Storage System SS4000-E — System partition, volume and file system information.