Service manual

1-34 AlphaServer GS80/160/320 Service Manual
1.9 System Partitioning
Partitions allow large systems to appear as several smaller ones either
from a hardware and/or software point of view.
NOTE: When considering partitions, it is helpful to separate two functions
resident on the standard I/O module: the SCM function and the SRM
function. Although all STD I/Os contain SCM code, only one is master
of the CSB and only one other may be eligible to become master. A
major reason for having more than two standard I/O modules in a
system is to fulfill the requirement that each partition, hard or soft,
have an SRM console.
1.9.1 Hard Partitions
GS80/160/320 systems may be hard partitioned on QBB boundaries. The
number of QBBs in a system dictates the maximum number of hard
partitions. Each hard partition requires at least one QBB that has
CPU(s), memory, and an I/O subsystem with a standard I/O module.
Table 1– 4 Rules Affecting Hard Partitions
Rule Rule Description
1
A hard partition requires one or more QBBs with CPUs, memory, and an
attached I/O subsystem(s) with at least one standard I/O module.
2 Hard partitions are set up on QBB boundaries.
3 The maximum number of standard I/O modules on the console serial bus is eight.
4 Hard partitions may have redundant consoles but are limited by rule 3.
5 Hard partitions are defined at the SCM firmware level.
For a full discussion of hardware partitions and how to create them, see
AlphaServer GS80/160/320 Getting Started with Partitions.