Typical Installation - Compaq StorageWorks HSZ80 Configuration And Cli Reference Manual

1–2 General Description

Typical Installation

Figure shows the major components, or basic building blocks, of the storage
subsystem that is comprised of the following:
One BA370 rack-mountable enclosure.
Two controllers, each supported by a cache module.
Two External Cache Batteries (ECBs) in one Storage Building Block (SBB),
which provide backup power to the cache modules during a primary power
failure.
One environmental monitoring unit (EMU) that monitors the subsystem's
environment and alerts the controller of equipment failures that could cause an
abnormal environment.
One Power Verification and Addressing (PVA) module that provides a unique
address to each enclosure in an extended subsystem.
Six I/O modules that integrate the SBB shelf with either an 8-bit single-ended,
16-bit single-ended, or 16-bit differential SCSI bus
Two cache modules, which support nonvolatile memory and dynamic cache
policies to protect the availability of its unwritten (write-back) data