Hardware Management Console (Hmc) - IBM pSeries 690 Service Manual

The media subsystem provides space for up to three media devices (diskette drive, CD-ROM drive, and
optional tape drive or DVD-RAM) in the front and two additional optional devices in the rear.

Hardware Management Console (HMC)

The Hardware Management Console (HMC) supports your system with features that allow you to manage
configuration and operation of partitions in a system, as well as add and remove hardware without
interrupting system operation.
In this book, a system that is managed by the HMC is referred to as the managed system. The HMC uses
its serial connection to the managed system to perform various functions. The HMC's main functions
include the following:
v Creating and maintaining a multiple partition environment
v Detecting, reporting, and storing changes in hardware conditions
v Acting as a service focal point for service representatives to determine an appropriate service strategy
Partitioning the system is similar to partitioning a hard drive. When you partition a hard drive, you divide a
single hard drive so that the operating system recognizes it as a number of separate hard drives. The
same holds true for the HMC's partitioning capabilities, except the HMC allows you to divide the system's
processors, memory, and I/O. On each of these divisions, you can install an operating system and use
each partition as you would a separate physical machine. This division of system resources is called a
logical partition.
The objective of partitioning is to provide users with the capability to split a single system into several
independent systems, each capable of running applications in multiple, independent environments
simultaneously. For example, partitioning makes it possible for a user to run a single application using
different sets of data on separate partitions, as if it were running independently on separate physical
systems.
Service representatives use Service Focal Point (SFP), an application that runs on the HMC, to start and
end their service calls. SFP provides service representatives with the serviceable event, vital product data
(VPD), and diagnostic information.
The HMC is a closed system. Additional applications cannot be installed on the HMC. All the tasks needed
to maintain the platform, the underlying operating system, and the HMC application code are available by
using the HMC's management applications.
Partition Standby and Full System Partition Power-On Options
Booting your system in partition standby is markedly different from booting your system in a traditional
single-machine full system partition. In partition standby, the system sets aside system memory for
partition management.
Partition Standby Memory Issues
Unique issues are associated with assigning memory to each partition created in partition standby. In
partition standby, the HMC allocates a portion of each assigned memory block to the system.
Each partition requires a minimum of 1 gigabyte (GB) of system memory. When you start creating
partitions, the system sets aside 256 megabytes (MB) of contiguous memory for its own use, and allocates
another 256 MB of contiguous memory for each 16 GB allocated.
Page Table Memory Usage: Partition page tables are additional memory required for a partition to
operate, and is in addition to the total logical memory size of a partition. The partition table is outside of a
partition's accessible memory. The partition page table must be constructed with contiguous real system
memory segments. Use the following table to help you keep track of the system's page-table memory
usage:
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Chapter 1. Reference Information