Ma8000/Ema12000 Storage Subsystem; Hsg80 Array Controller - Compaq 112726-001 - ProLiant - 6500 Administrator's Manual

2-4 Compaq Parallel Database Cluster Model PDC/O5000 for Oracle8i and Windows 2000 Administrator Guide

MA8000/EMA12000 Storage Subsystem

HSG80 Array Controller

The MA8000/EMA12000 Storage Subsystem is the shared storage solution for
the PDC/O5000. Each storage subsystem consists of one controller enclosure
and up to six disk enclosures.
For detailed information about storage subsystem components, refer to the
Compaq StorageWorks documentation provided with the
MA8000/EMA12000 Storage Subsystem.
Controller Enclosure Components
The controller enclosure for the MA8000/EMA12000 Storage Subsystem
houses the two HSG80 Array Controllers, one cache module for each
controller, an environmental monitoring unit (EMU), one or two power
supplies, and three dual-speed fans. In addition, the controller enclosure
houses the six I/O modules that connect the enclosure's six SCSI buses to up
to six disk enclosures.
Disk Enclosure Components
Each disk enclosure houses up to 12 or 14 form factor hard disk drives,
depending on the number of SCSI buses connected to the enclosure's I/O
module. A single-bus or dual-bus I/O module in each disk enclosure is
connected by UltraSCSI cable to one single-bus I/O module in the controller
enclosure. Disk enclosures using a single-bus I/O module can contain up to
12 disk drives. Disk enclosures using both connectors on a dual-bus I/O
module can contain up to 14 disk drives (7 per SCSI bus). When you have
more than three disk enclosures in your subsystem, they must all use
single-bus I/O modules, for a maximum of 72 disk drives in each
MA8000/EMA12000 Storage Subsystem.
Each disk enclosure also contains redundant power supplies, an EMU, and two
variable-speed blowers.
Two dual-port HSG80 Array Controllers are installed in the controller
enclosure of each MA8000/EMA12000 Storage Subsystem.
From the perspective of the cluster nodes, each HSG80 Array Controller port
is simply another device connected to one of the cluster's I/O connection paths
between the host adapters and the MA8000/EMA12000 Storage Subsystems.
Consequently, each node sends its I/O requests to the array controllers just as