Configuration for iSeries (SAP Library - SAP Memory Management (BC-CST-MM))

Configuration for iSeries

For information about how the memory management system is implemented on iSeries, see Memory Management on iSeries.

In the tables below, you will find information about the necessary settings for the memory management system.

Check that your host system fulfills the SAP recommendations for main storage and free space in additional memory (ASPs).

Check the resources and system-specific requirements on all host systems on which a server is to be installed. For more information, see Checking the Hardware and Operating System of the Host System.

The profile parameters that the memory management system uses are set automatically and are stored in the instance profile used by each SAP Web Application Server in your system. For more information, see Profiles.

If you modify the profiles directly with a system editor, you must perform an error check. For more information, see Checking the Hardware and Operating System of the Host System.

The values listed in the following table for the host systems and servers should ensure the best possible operation of your SAP Web Application Server.

Main and Unprotected Storage on the Host System

Resource	SAP Recommendation
Free memory area ASP 1	Minimum: 2 GB Recommend 4-6 GB
Main storage	512 MB is sufficient for approx. 15 dialog users. 1024 MB is sufficient for approx. 50 dialog users. You will achieve performance advantages with higher values. These values are valid for hosts on which only one SAP System runs. If other SAP Systems run on the host, contact the Hardware Competence Center or your system consultant.
Storage pool 2	All SAP jobs run in pool 2 according to the default values. Therefore, make as much space available for pool 2. 250 MB is the absolute minimum.

Recommended Profile Parameters

Parameter	Recommended Value
abap/heaplimit	40000000 (40 mil. bytes)
abap/heap_area_dia	2000000000 (2 GB)
abap/heap_area_nondia	2000000000 (2 GB)
abap/heap_area_total: Limit for Heap Memory	2000000000 (2 GB)
em/initial_size_MB: Size of the Extended Memory Pool	8092 (8 GB) Minimum 64 MB
em/stat_log_size_MB: Statistics - User Context Size	20
em/stat_log_timeout: Statistics - User Context Size	600
rdisp/ROLL_MAXFS: Maximum Roll File Size	0
rdisp/ROLL_SHM: Roll Buffer Size	0
rdisp/PG_MAXFS: Maximum Size of the SAP Paging File	32768 blocks
rdisp/PG_SHM: Size of the Paging Buffer	32768 blocks
ztta/roll_area: Roll Area	16773120 (16 MB roll area per internal mode)
ztta/roll_first: Size of the Initial Allocation from the Roll Area	1
ztta/roll_extension: Limit for Extended Memory	2000000000 (2 GB extended memory per user)

Parameter	Recommended Value (Use)
em/stat_log_size_MB	20 (Size above which the user context is logged for statistical purposes)
em/stat_log_size_timeout	600 (Interval in which statistics are gathered for the user context size)
rdisp/PG_MAXFS	32768 (Maximum size of the ABAP paging file - 64 MB)
rdisp/PG_SHM	32768 (Size of the paging buffer - 64 MB)

Caution

The values listed here are recommended basic values. In the course of monitoring and optimizing your SAP System, you may have to change these values under certain circumstances. For more information, refer to Monitoring the Memory Management System and Temporary Memory on iSeries.

Note

Check the changes to the system profiles using the program rspfpar. For more information, see Checking the Hardware and Operating System of the Host System.