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

2-18 Compaq Parallel Database Cluster Model PDC/O2000 for Oracle8i and Windows 2000 Administrator Guide
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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: c-ch2 Cluster Architecture.doc Last Saved On: 6/13/01 10:21 AM
Table 2-2
Features of Active/Standby and Active/Active Configurations for Redundant Fibre Channel
Fabrics
continued
I/O Path Configuration Advantage Disadvantage
Active/active with two or more
RA4000/RA4100 Arrays
Provides a small but measurable
improvement in I/O performance
over the active/standby
configuration because both Fibre
Host Adapters in each node and
both Fibre Channel SAN
Switches are simultaneously
active. This improvement can be
meaningful for customers with
large cluster databases or high
I/O transaction requirements.
Provides better load balancing
between the two Storage Hubs
than the active/standby
configuration. Both Fibre
Channel SAN Switches are
connected to the same or
equivalent numbers of both
active and standby array
controllers in the
RA4000/RA4100 Arrays.
Does not provide true cabling
symmetry between Fibre
Channel SAN Switches and array
controllers if you consistently
configure the top or rightmost
array controller as the active
controller. Each Fibre Channel
SAN Switch is cabled to top
(active) array controllers in some
RA4000/RA4100 Arrays and
bottom (standby) controllers in
others. You can achieve cabling
symmetry if you configure the
bottom array controller in some
RA4000/RA4100 Arrays as
active. However, this requires
using Secure Path to configure
the lower array controller as
active if it is in standby mode.