SAP Default values of zero administration memory management up to kernel version 7.2x

Default values of zero administration memory management up to kernel version 7.2x

[RAM] = size of the physical main memory
[PM] = value of the profile parameter PHYS_MEMSIZE (standard value=[RAM])
[US] = factor dependent on [PM] - calculated automatically

Profile parameter	Standard 32-bit	Standard 64-bit	Unit:
em/initial_size_MB	[PM]	[PM]	MB
em/max_size_MB	20000	1.5 * [PM]	MB
em/address_space_MB	512	4096	MB
ztta/roll_first	1	1	byte
ztta/roll_area	2000000	3000000	byte
ztta/roll_extension	2000000000	2000000000	byte
abap/heap_area_dia	2000000000	2000000000	byte
abap/heap_area_nondia	2000000000	0	byte
abap/heap_area_total	2000000000	[PM]*1048576	byte
rdisp/ROLL_MAXFS	[US] * 100	[US] * 100	8KB block
rdisp/ROLL_SHM	[US] * 100	[US] * 100	8KB block
rdisp/PG_MAXFS	32768	32768	8KB block
rdisp/PG_SHM	[US] * 50	[US] * 50	8KB block

Important:

em/global_area_MB + abap/share_objects_size_MB + ztta/roll_extension
    must fit in the following address window: 
em/address_space_MB

If ("em/global_area_MB" + "abap/shared_objects_size_MB") > "em/address_space_MB", the system does not start (error in "dev_disp" dispatcher).

If ("em/global_area_MB" + "abap/shared_objects_size_MB") < "em/address_space_MB", ("em/address_space_MB" – "em/globa_area_MB" – "abap/shared_objects_size_MB") is available for the extended memory. The value of "ztta/roll_extension" acts as a quota.

At present, "em/address_space_MB" cannot be calculated automatically taking into account the specified parameters in kernel versions < 7.40.

Default values of zero administration memory management as of kernel version 7.40

[RAM] = size of the physical main memory

In 7.40, parameter values can contain formulas. The expression $(Parameter) in the value of a parameter references the value of the parameter with the name Parameter.

Profile parameter	Standard 64-bit	Unit:
PHYS_MEMSIZE	1.0 * [RAM]	MB
em/initial_size_MB	0.7 * $(PHYS_MEMSIZE)	MB
em/max_size_MB	1.5 * $(PHYS_MEMSIZE)	MB
abap/buffersize	$(em/initial_size_MB) * 1024 * 0.15	KB
abap/programs	$(abap/buffersize) / 4	Entries
abap/heap_area_dia	2000000000	byte
abap/heap_area_nondia	0	byte
abap/heap_area_total	1048576 * $(PHYS_MEMSIZE)	byte
abap/shared_objects_size_MB	$(em/initial_size_MB) * 0.02	MB
em/address_space_MB	$(em/initial_size_MB)	MB
em/max_size_MB	$(PHYS_MEMSIZE) * 1.5	MB
rdisp/wp_ca_blk_no	$(rdisp/elem_per_queue) * 3	Entries
rdisp/PG_SHM	max(min(1000+40*max(5,floor(($(PHYS_MEMSIZE)-128)   *25/128)),16384),1024)	8KB block
rdisp/PG_MAXFS	32768	8KB block
rsdb/ntab/entrycount	$(zcsa/db_max_buftab)	Entries
rsdb/ntab/ftabsize	min(500000, ($(rsdb/ntab/entrycount)))	KB
rsts/ccc/cache07	$(rsts/ccc/cachesize) * 0.1	byte
rtbb/buffer_length	$(zcsa/table_buffer_area) * 0.1 / 1024	KB
rtbb/max_tables	$(zcsa/db_max_buftab) * 0.1	Entries
zcsa/table_buffer_area	max(30000000,$(em/initial_size_MB) * 1024 * 1024 * 0.05)	byte
ztta/roll_extension	2000000000