Solution : https://service.sap.com/sap/support/notes/329021 (SAP Service marketplace login required)
Key words : 
symptom short dumps occur, open spool handle, maximum parameter setting, increasingly larger areas, parameter em/global_area_mb, error text spool_internal_error, parameter em/initial_size_mb, em/initial_size_mb, terms spool_internal_error, requested areas
Related Notes : 
       
| 1467134 | Signal 11 occurs after EgAlloc() fails | 
| 923610 | Memory parameter recommendations for banking systems | 
| 789477 | Large extended memory on AIX (64-bit) as of Kernel 6.20 | 
| 459208 | CST Patch Collection 51 2001 | 
| 445533 | Lots of extended memory on AIX (64 bit) | 
| 318846 | Installing the 4.6D kernel in 4.6A/B/C SAP systems | 
| 19466 | Downloading SAP kernel patches |