Compaq Parallel Database Cluster Model PDC/O1000 for Oracle8i and Windows 2000 Administrator Guide

Architecture 2-5
Compaq Confidential – Need to Know Required
Writer: John Blackburn Project: Compaq Parallel Database Cluster Model PDC/O1000 for Oracle8i and Windows 2000 Administrator Guide
Comments:
Part Number: 225083-002 File Name: c-ch2 Cluster Architecture.doc Last Saved On: 6/11/01 11:20 AM
RA4000 Array Controller
One single-port RA4000 Array Controller is installed in each RA4000 Array
or RA4100 Array. If the array controller fails, the cluster nodes cannot access
the shared storage disks in that array.
From the perspective of the cluster nodes, the RA4000 Array Controller is
simply another device connected to one of the cluster’s I/O paths.
Consequently, each node sends its I/O requests to the RA4000 Array
Controller just as it would to any SCSI device. The RA4000 Array Controller
receives the I/O requests from the nodes and directs them to the shared storage
disks to which it has been configured. Because the array controller processes
the I/O requests, the cluster nodes are not burdened with the I/O processing
tasks associated with reading and writing data to multiple shared storage
devices.
For more information about the RA4000 Array Controller, refer to
the Compaq StorageWorks RAID Array 4000 User Guide or the
Compaq StorageWorks RAID Array 4100 User Guide.
Fibre Channel SAN Switch
One Fibre Channel SAN Switch is installed between cluster nodes and shared
storage arrays in a PDC/O1000 cluster to create a non-redundant Fibre
Channel Fabric.
An 8-port or 16-port Fibre Channel SAN Switch can be used. The choice of an
8-port or 16-port Fibre Channel SAN Switch is determined by your hardware
requirements. For example, a non-redundant Fibre Channel Fabric with four
Fibre Host Adapters and five or more RA4000/RA4100 Arrays would require
a 16-port Fibre Channel SAN Switch.
The Fibre Channel SAN Switch provides full 100 MBps bandwidth on every
port. Adding new devices to ports on the Fibre Channel SAN Switch increases
the aggregate bandwidth.
Fibre Channel SAN Switch is used to connect one Fibre Host Adapter in each
cluster node to the array controller in the RA4000/RA4100 Arrays. The Fibre
Host Adapter in each node, the Fibre Channel SAN Switch, and the
RA4000/RA41000 Arrays to which they are connected belong to the same
non-redundant Fibre Channel Fabric.