Compaq Parallel Database Cluster Model PDC/O2000 for Oracle8i and Windows 2000 Administrator Guide

Cluster Planning 4-5
Compaq Confidential – Need to Know Required
Writer: John Blackburn Project: Compaq Parallel Database Cluster Model PDC/O2000 for Oracle8i and Windows 2000 Administrator Guide Comments:
Part Number: 225082-002 File Name: e-ch4 Cluster Planning.doc Last Saved On: 6/13/01 10:25 AM
Planning Shared Storage Components for
Redundant Fibre Channel Arbitrated Loops
Several key components make up the shared storage subsystem for the
PDC/O2000. Each redundant Fibre Channel Arbitrated Loop (FC-AL) in a
PDC/O2000 uses these hardware components:
■ Two or more Fibre Host Adapters in each node
■ Two or more Compaq StorageWorks Storage Hubs (Storage Hubs) or
Compaq StorageWorks FC-AL Switches (FC-AL Switches)
■ One or more RA4000 Arrays or RA4100 Arrays
■ Two single-port RA4000 Array Controllers installed in each
RA4000/RA4100 Array. Only one array controller in the
RA4000/RA4100 Array is active at any one time; the other is the
standby array controller.
NOTE: For more information about redundant Fibre Channel Arbitrated Loops (FC-ALs) in
a PDC/O2000 cluster, see Chapter 2, “Cluster Architecture.”
The FC-AL Switches are available in an 8-port model that can be expanded to
11 ports. The Storage Hubs are available in 7-port and 12-port models.
To determine which FC-AL Switch or Storage Hub model is appropriate for a
redundant FC-AL in your cluster, identify the total number of nodes and
RA4000/RA4100 Arrays connected to that redundant FC-AL. For FC-AL
Switches, if the combined number of nodes and arrays exceeds eight, you must
use 11-port FC-AL Switches. For Storage Hubs, if the combined number of
nodes and arrays exceeds seven, you must use Storage Hub 12s. Also consider
the possibility of future cluster growth when you select your models.
The number of RA4000/RA4100 Arrays and shared disk drives used in a
PDC/O2000 depends on the amount of shared storage space required by the
database, the hardware RAID levels used on the shared storage disks, and the
number and storage capacity of disk drives installed in the enclosures. Refer to
“Raw Data Storage and Database Size” in this chapter for more details.
NOTE: For improved I/O performance and cluster integrity, as you increase the number of
nodes in a PDC/O2000 cluster, you should also increase the aggregate bandwidth of the
shared storage subsystem by adding more or higher-capacity disk drives.