It was bad news! Drive number 4 on the RHS of the XSR failed. If this happens, because the disks are set at RAID 5 it means that although there will be a slowing down in performance, no data is actually lost. So, rather carefully I pulled the disk in its enclosure out of the XSR chassis.
My XSR is a 5.6 Terrabyte model which means you get 2.2 Terrabytes per side. It is made up from 14 400Gig Hitachi drives mounted in these cradles. I did look at buying the spares pack when I bought the RAID, but at around $3000 it looked expensive.

Could I find a replacement 'blade' on the Apple Store? No. Could I find any info after an afternoon of Googling? No. One thing for it, phone a friend.

"Try Maplin" was the answer from an office behind Regent Street. Which is exactly what I did, which would have worked if they had had any 400G drives.
The problem is that every where now seems to stock Serial ATA (SATA) drives. These are great for stuffing in a G5 or MacPro but pretty useless for an XSR as it uses AT Attachment (IDE) drives. After more Googling I finally found a place in the UK with some spare drives and immediately ordered one and to my joy it arrived the next day. After swapping the drive out of the cradle and replacing it with the new drive, I was confronted by a new problem. What the hell do I do now?
Yeup, you guessed it, phone another friend! "It should automatically rebuild itself" was the advice and thats exactly what happened.

It took about 8 hours for the RAID to rebuild itself completely but I was amazed at the ease in which I could repair the storage beast. I didn't lose a single frame of video either. Oh, the cost? $100.