EgInit: EsCreateShared() failed. info='EG_GLOBAL_AREA'...

The startup of a 640 kernel fails when you change from 620 to 640. The following error messages appear in the dispatcher:

*** ERROR => ESSHM: ====================> ERROR <====================
*** ERROR => ESSHM: Error during Execution for Work Process 0 in
  SHM_EsCreateShared
*** ERROR => ESSHM: esSHMAllocateBlock returned 10 [esuxshm.c    1871]
*** ERROR => ESSHM: ====================> ERROR <====================
*** ERROR => EgInit: EsCreateShared() failed. info='EG_GLOBAL_AREA',
  blocks=274, rc=1
*** ERROR => DpEmInit: EmInit (1) [dpxxdisp.c   7928]
*** ERROR => DpMemInit: DpEmInit (-1) [dpxxdisp.c   7867]
*** DP_FATAL_ERROR => DpSapEnvInit: DpMemInit
*** DISPATCHER EMERGENCY SHUTDOWN ***

The startup with the 6.40 kernel fails because the EG memory requirement with 640 has increased. In kernel 6.20, the requirement for EG was determined by the em/global_area_MB parameter alone. (The default is 96 MB).

With the 6.40 kernel, the ABAP Shared Object are added again and require additional address space in the EG. The size for shared objects is determined by the abap/shared_object_size_MB parameter (the default is 20 MB).
If em/global_area_MB is set too high, then the entire EG exceeds 256 MB. That is, the following applies in particular for AIX:

em/global_area_MB + abap/shared_object_size_MB < ES/SHM_SEG_SIZE

The default for this is:

em/global_area_MB + 20 < 255

If this is not sufficient for the EG area, you must increase the size segment but, at the same time, you must decrease the number of segments proportionally to achieve the same memory requirement: (several ES/SHM_MAX_SHARED_SEGS>1 segments are not sufficient):

A set-up proposal for an increased EG requirement (otherwise, the standard is sufficient) could look as follows:

Recommendation Standard Useful area

ES/TABLE = SHM_SEGS
ES/SHM_PROC_SEG_COUNT = 16    64   (2..64)
ES/SHM_MAX_PRIV_SEGS = 15    63   (1..63)
ES/SHM_MAX_SHARED_SEGS = 1     1   (currently only 1)
ES/SHM_SEG_SIZE = 1024   256   (256..8192)

That is, the segment size was reduced by a factor of 4 and the number of segments were reduced by a factor of 4. The following applies for this configuration:

em/global_area_MB + abap/shared_objects_size_MB < 1024

Restriction:
See note 785365: Up until the following kernel patch level

620 patch level 1729
640 patch level 44

the following applies:

em/global_area_MB + abap/shared_objects_size_MB < 2048



Solution

Configure the instance profile accordingly.