Setting the Profile Parameters (UNIX)
Use
The ideal parameter settings depend on the hardware resources available (main memory and swap space) on the one hand and the system load on the other, that is, the maximum/average number of (active) users working on an application server.
Procedure
The following table serves as a guideline for setting profile parameters on UNIX platforms.
Memory management on IBM AIX is very different from on other UNIX systems. For this reason, setting the parameters under AIX is dealt with in a separate section (see
|
Parameter |
Unit |
Default setting |
Recommendation: |
Comment |
| abap/heaplimit: Work Process Restart |
Bytes |
40000000 (40 MB) |
20000000 |
|
| ztta/roll_extension: Limit for Extended Memory |
Bytes |
250000000 (250 MB) |
Possibly more (approx. 500MB), depending on the application |
If there is a large amount of memory available, you can also increase the value if certain programs are taking up lots of memory. |
| abap/heap_area_dia: Heap Memory Limit for Dialog Work Processes |
Bytes |
80000000 (80 MB) |
200000000-500000000 |
|
| abap/heap_area_nondia: Heap Memory Limit |
Bytes |
40000000 (40 MB) |
900000000 (900 MB) |
Siemens-Nixdorf: max. 350 MB HP-UX: 600000000 (600 MB) |
| abap/heap_area_total: Heap Memory Limit |
Bytes |
800000000 (800 MB) |
physical memory + swap space - allocated virtual memory |
You can monitor the physical memory and swap space using transaction ST06. Allocated virtual memory consists of allocated memory from:
You can view this using transaction ST02 ® Detail Analysis Menu ® Storage. |
| em/initial_size_MB: Size of Extended Memory |
Megabyte (MB) |
128 |
200 to 500 MB, approximately 5 MB for each SAP user |
|
| rdisp/ROLL_SHM: Roll Buffer Size |
8 KB blocks |
0 |
8000 |
Unless the Tune summary in the CCMS (Transaction ST02) (under Monitoring the Memory Management System) specifies that a larger roll buffer is required, do not set a value larger than 12500 (100 MB).Absolute upper limit: 250000 blocks (2 GB) for special applications (file system must be large enough) |
| rdisp/ROLL_MAXFS: Maximum Roll File Size |
8 KB blocks |
2048 |
64000 |
Absolute upper limit: 250000 blocks (2 GB) for special applications (file system must be large enough) |
| rdisp/PG_SHM: Size of the Paging Buffer |
8 KB blocks |
0 |
1024 |
Absolute upper limit: 250000 blocks (2 GB) for special applications (file system must be large enough) |
| rdisp/PG_MAXFS: Maximum Size of the SAP Paging File |
8 KB blocks |
2048 |
32768 |
Absolute upper limit: 250000 blocks (2 GB) for special applications (file system must be large enough) |
| ztta/roll_first: Size of the Initial Allocation from the Roll Area |
Bytes |
1000000 (1 MB) |
1 byte |
One (1) byte means that only one small amount of memory specifically for that system is allocated and then goes in to the extended memory. A high value (1 MB or more) may be useful if there is not a lot of extended memory available (see Recognizing and Correcting Problems). |
| ztta/roll_area: Roll Area |
Bytes |
6500000 (6.5 MB) |
6500000 (6.5 MB) |
|
| em/blocksize_KB: Segment Size for the Extended Memory |
Kbyte |
1024 (1 MB) |
1024 (1 MB) |
You may not change the default value. |
The 64-bit SAP kernel can be used with 64-bit operating systems. In this case, the parameters can be set much higher. This is described under