HP,
http://h18006.www1.hp.com/products/s...ise/index.html
The controller is called HSV110 and they are sandwiched between the loop switches in the pic at the beginning of the thread. Each disk shelf - one is at the top of the pic - has two power supplies - white and black cables - connected to separate power controllers on separate power circuits. The shelf is on two fiber loops connected to separate loop switches. There is a separate controller on each loop. The four switches are for the left and right sides of the cab, bottom and top.
The controllers are connected to separate SAN switches and each host computer has a separate fibre-channel card on a separate I/O bus connected to each SAN switch.
The object is to survive the failure of any single component including a disk shelf which comprises up to 14 x 306 GB disks. A cab can have 12 shelves - the one pictured has 6 and has lower-capacity disks as the cost/storage density trade off very much favors that.
I'm using RAID 0, 1 and 0+1 - 0+1 in DEC parlance being stripes + controller based mirroring. The critical data use VMS host-based shadowing with 3-member shadow sets, one member at a DT site at what was formerly the USAF Space Command
A lot less complicated than passive crossover networks which completely confound me.
John