Compaq StorageWorks UltraSCSI RAID Enclosure (DS-BA370 Series) User's Guide (EK-BA370-UG. C02, September 1998)

Introducing the UltraSCSI RAID Enclosure
UltraSCSI RAID Enclosure 1–13
Compaq recommends using this configuration to eliminate all single
points of power failure.
Dual Controllers
Establishing a subsystem with a
dual redundant configuration
(two
UltraSCSI controllers, two cache modules, and ECBs) is the most
effective and efficient method of ensuring continuous subsystem
operation in the event of a component failure.
UltraSCSI Bus Expansion
Some controllers support expanding the UltraSCSI bus from the
master enclosure to two expansion enclosures. Refer to the array
controller documentation to determine if the controller supports this
feature.