Intel AS/400 RISC Server - Manual (Page 279)

16.10 5XX IOP vs IOPLess effects on IPL Performance (Normal)
Measurement units are in minutes and seconds .
28:18 26:59 Total
2:52 2:32 OS/400
7:20 6:43 SLIC
18:06 17:44 Hardware
iV5R4
GA7 Firmware
16 Way IOPLess
570
7476
256 GB
924 DASD
iV5R4
GA7 Firmware
16 Way IOP
570
7476
256 GB
924 DASD
Table 16.10.2 Normal IPL - Power-On (Cold Start)
16.11 IPL Tips
Although IPL duration is highly dependent on hardware and software configuration, there are tasks that
can be performed to reduce the amount of time required for the system to perform an IPL. The following
is a partial list of recommendations for IPL performance:
y
Remove unnecessary spool files. Use the Display Job Tables (DSPJOBTBL) command to monitor
the size of the job table(s) on the system. Change IPL Attributes (CHGIPLA) command can be used
to compress job tables if there is a large number of available job table entries. The IPL to compress
the tables maybe longer, so try to plan it along with a normal maintenance IPL where you have the
time to wait for the table to compress.
y
Reduce the number of device descriptions by removing any obsolete device descriptions.
y Control the level of hardware diagnostics by setting the CHGIPLA command to specify
HDWDIAG(*MIN), the system will perform only a minimum, critical set of hardware diagnostics.
This type of IPL is appropriate in most cases. The exceptions include a suspected hardware problem,
or when new hardware, such as additional memory, is being introduced to the system.
y Reduce the amount of rebuild time for access paths during an IPL by using System Managed Access
Path Protection (SMAPP). The IBM i operating system Backup and Recovery book (SC41-5304)
describes this method for protecting access paths from long recovery times during an IPL.
y
For additional information on how to improve IPL performance, refer to IBM i operating system
Basic System Operation, Administration, and Problem Handling (SC41-5206) - or to the redbook The
System Administrator’s Companion to IBM i operating system Availability and Recovery
(SG24-2161).
IBM i 6.1 Performance Capabilities Reference - January/April/October 2008
©
Copyright IBM Corp. 2008 Chapter 16 IPL Performance 279