Setting the Profile Parameters (IBM i)

Use

The optimum parameter settings are dependent on:

Available hardware resources (main memory and free auxiliary storage)
System load, that is average or maximum number of active users on an application server

Procedure

The following table is a guide for setting the profile parameters for the IBM i platform:

Parameter	Unit	Default Value	Recommendation	Comment
abap/heaplimit: Work Process Restart	Bytes	40000000 (40 MB)	40 MB
ztta/roll extension: Extended Memory Limit	Bytes	2 GB	Possibly lower depending on application
abap/heap_area_dia: Heap Memory Limit for Dialog Work Processes	Bytes	2 GB	2 GB
abap/heap_area_nondia: Heap Memory Limit for Non-Dialog Work Processes	Bytes	2 GB	2 GB
abap/heap_area_total: Heap Memory Limit	Bytes	2 GB	2 GB	You can use the operating system monitor (ST06) to monitor physical storage and ASP usage. Allocated unprotected temporary storage includes the allocated memory of: All SAP system instances Database buffers and processes Operating system You can look at this in detail using transaction ST02 Detail analysis Storage .
em/initial_size_MB: Extended Memory Pool Size	MB	4092	Minimum 64 MB
rdisp/ROLL_SHM: Roll Buffer Size	8 KB blocks	16384	32768	Do not define a value higher than 12500 (100 MB) unless the CCMS Tune Summary (Transaction ST02) under Monitoring the Memory Management System states that a larger roll buffer is required. Absolute upper limit: 250000 blocks (2 GB) for special applications
rdisp/ROLL_MAXFS: Maximum Roll File Size	8 KB blocks	32768	32768	Absolute upper limit: 250000 blocks (2 GB) for special applications
rdisp/PG_SHM: Paging Buffer Size	8 KB blocks	32768	32768 (the same value as rdisp/PG_MAXFS)	Absolute upper limit: 250000 blocks (2 GB) for special applications
rdisp/PG_MAXFS: Maximum Size of the SAP Paging File	8 KB blocks	32768	32768	Absolute upper limit: 250000 blocks (2 GB) for special applications
ztta/roll_first: Initial Allocation Size from the Roll Area	Bytes	1 byte	1 byte	This value is set automatically and cannot be changed.
ztta/roll_area: Roll Area	Bytes	3 MB	3 MB	This value is set automatically and cannot be changed.
em/blocksize_KB: Segment Size for the Extended Memory	KB	4096 (4 MB)	4096 (4 MB)	Do not change the default value.