Installation guide

Configuration

Rules

2-11

When you are defining two partitions, you may have from two to three memory

modules (GS60E system) or from two to five memory modules (GS140 system),

depending on the number of CPU and I/O modules in the system. Memory is

always allocated on module boundaries. Set the interleave environment vari-

able to none, as noted in Chapter 4.

The console firmware allocates the largest sized module to partition 0, and the

smallest module to partition 1. It then attempts to distribute the remaining

modules such that as equal an amount is given to both partitions as is possible.

Figure 2–5 shows some examples. Item A declares that when there are an even

number of modules of equal size, the memory is divided equally. Item B illus-

trates an odd number of modules of equal size. Here, the distribution is as

equal as possible, with the largest amount of memory going to partition 0, and

the next-largest, to partition 1.

Item C shows some examples of a series of modules of varying size. In general,

the largest memory module is allocated to partition 0, and the smallest, to parti-

tion 1. The remaining modules are divided so as to make the allocation for the

two partitions as equal as possible. When a situation arises to make both parti-

tions unequal with the same ratio, the firmware makes partition 0 the largest

partition (case 3, below).

Here, the 4 -Gbyte memory is allocated to partition 0, and the 1-Gbyte

memory is allocated to partition 1. There are two remaining 2-Gbyte mod-

ules, and they are distributed so as to make the partitions as equal as possi-

ble, giving both 2-Gbyte modules to partition 1, creating partition 0 with 4

Gbytes and partition 1 with 5 Gbytes.

Here, a 2-Gbyte memory is allocated to partition 0, and the 1-Gbyte memory

is allocated to partition 1. The remaining 2-Gbyte memory is given to parti-

tion 1, since a 3-Gbyte/2-Gbyte allocation is more equal than allocating 4

Gbytes to partition 0 and 1 Gbyte to partition 1.

Here, a 2-Gbyte memory is allocated to partition 0, and a 1-Gbyte memory is

allocated to partition 1. Either way the remaining 2-Gbyte memories are

allocated (both to partition 1, or 1 to partition 0 and 1 to partition 1), the

memory allocation will be 3 Gbytes/2 Gbytes, so the default is to make parti-

tion 0 the largest partition.