It is not clear which maximum values can be assigned to specific parameters in which kernel release for SAP memory management.
Current parameter settings:
32-bit 64-bit
Releases lower than 46D:
ztta/roll_extension <2GB <2GB
abap/heap_area_total <2GB <2GB
0 = unlimited Remark 5.)
abap/heap_area_(non)dia <2GB <2GB
0 = unlimited Remark 5.)
ES/SHM_SEG_COUNT R/3 <4000 R/3 8000
OS 4096 OS unlimited
ES/SHM_USER_COUNT R/3 <4000 R/3 4096 Remark 1.)
Release 46D:
ztta/roll_extension <2GB <4GB Remark 5.) + 6.)
abap/heap_area_total 64-bit float value
0 = unlimited Remark 5.)
abap/heap_area_(non)dia <2GB <2GB
0 = unlimited Remark 5.)
EM/MAX_SIZE_MB up to 46D Patch Level 569, Remark 4.)
(linux: em/max_size_MB)
EM/TOTAL_SIZE_MB as of 46D Patch Level 570, Remark 4.)
ES/SHM_SEG_COUNT R/3 <4000 R/3 8000, Remark 3.)
OS 4096 OS unlimited
ES/SHM_USER_COUNT R/3 <4000 R/3 8000, Remarks1.)+ 2.)
ES/SHM_PROC_SEG_COUNT <=9 <=64 Remark 5.)
ES/SHM_MAX_PRIV_SEGS <=8 <=63 Remark 5.)
Releases 6.10 up to 6.40:
ztta/roll_extension <2GB unlimited
abap/heap_area_total 64-bit float value
0 = unlimited Remark 5.)
abap/heap_area_(non)dia <2GB <2GB
0 = unlimited Remark 5.)
ES/SHM_SEG_COUNT R/3 <4000 R/3 8192
OS 4096 OS unlimited
ES/SHM_USER_COUNT R/3 <4000 R/3 8192, Remarks 1.)+ 2.)
ES/SHM_PROC_SEG_COUNT <=9 <=64, due to roll_extension
ES/SHM_MAX_PRIV_SEGS <=8 <=63, due toroll_extension
Remark 5.)
EM/TOTAL_SIZE_MB 64-bit Float Value
Comments:
1. (Status on August 6, 2001) Depends on the size of the Select mask of the dispatcher and the gateway. Both can only contain 2K of handles. This means that the maximum number of (Gui and RFC) contexts is limited, as is the maximum number of entries in rdisp/tm_max_no. An entry that makes demands on ES/SHM_USER_COUNT causes at least one entry that makes demands on ES/SHM_SEG_COUNT. This means you must set ES/SHM_SEG_COUNT to be larger than or equal to ES/SHM_USER_COUNT: Hence the extension in Remark 2).
2. (Status on October 24, 2001) Is increased to 8192 in 6.20 in the default and in 46D and 6.10 with patches: Maximum ES/SHM_USER_COUNT = 8192 is valid for the following Patch Level: 46D = 739; 6.10 = 220; 6.20 contained in the default settings. The following applies for older patch level versions of these releases: Maximum ES/SHM_USER_COUNT = 4096
3. As of Patch Level 579.
4. The parameter(s) only apply to Linux (em/max_size_MB) and AIX (EM/MAX_SIZE_MB, but only up to the specified patch level). On these platforms, the maximum size of the extended memory is not limited by em/initial_size_MB. This is important to limit the total memory used, otherwise, in a worst case scenario, the system may run out of swap space and a paging collapse may occur (see Note 517006 for further information). This means that the value of the parameter must be considerably lower than the size of the swap space available.
5. In this context, see Note 548845, which does not allow internal modes that are larger than 2 GB.
6. ztta/roll_extension must be smaller than
(4096 - ztta/max_memreq_MB) * 1024 * 1024 - 1