Specifications

4–15

Compaq HSG80 Array Controller ACS Version 8.4 Configuration and CLI Reference Guide

■ If you’re using more than one mirrorset in your subsystem, you should put the

first member of each mirrorset on different buses as shown in Figure 4–6. (The

first member of a mirrorset is the first disk drive you add.)

When a controller receives a request to read data from a mirrorset, it typically

accesses the first member of the mirrorset. Read access depends upon the read

source switches, as described in “Read Source,” page 4–40. If you have several

mirrorsets in your subsystem and their first members are on the same bus, that

bus will be forced to handle the majority of traffic to your mirrorsets. When a

controller receives a request to write data to a mirrorset, it accesses and writes to

all members.

Figure 4–6. First Mirrorset Members on Different Buses

To avoid an I/O bottleneck on one bus, you can simply put the first members on

different buses. Additionally, you can set the read-source switch to Round Robin.

See “Read Source,” page 4–40, for more information about this switch.

Table 4–4. Key to Figure 4–6 First Mirrorset Members on Different Buses

Item Description

➀ First member of Mirrorset 1

➁ First member of Mirrorset 2

CXO5506B