Well I don't see what your hardware is. Machine type, RAID type, etc..
But in most cases RAIDS have a designated enumeration, the one's I know start with drive 0. since yours shows Drive 7 I am going to assume (again not knowing your hardware setup) that it has 8 bays. So slots 0-3 are empty, and 4-7 have your drives. Either that or it's a split backplane, and for some reason it starts at 4, but I am guessing it has 8 slots.
That's why you have a drive 7, that's the number matching it's physical slot. If you look at the front of the machine careful, I bet you will see the drive designations, 0,1,2 etc.. That's when you get an error, it will say Drive 3 bad, you know exactly which one to pull or replace.
Since this happened after the update, I'd say your hardware needs a firmware patch, the current firmware level probably doesn't support the ESX U4. Have you tried calling your vendor to see if they have a new patch? Or perhaps this machine is not on the HCL for ESX?
If that's the case then, you obviously don't have hardware issues, just ignore the hardware issue. Reinstalling ESX would probably fix it, trying to figure out where the problem is for this is a pain. Since your other servers are working you can rebuild it inside of 10 minutes (not a upgrade a new install and retain the VMFS).
