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AIX: SAP kernel 754 with improved performance

By Harald Duvenbeck posted Thu February 23, 2023 12:17 PM


Last week, SAP Kernel 754 on AIX became available as part of SAP general release of kernel 754 as a so-called "downward compatible kernel".
(see SAP Note 3156866 - Using Kernel 7.54 instead of Kernel 7.40, 7.41, 7.42, 7.45, 7.49 or 7.53)

Downwards compatibility means that you can replace SAP kernel 753 with 754 in any SAP system that is based on :

  • NetWeaver 7.4 (ABAP and Java)
  • NetWeaver 7.5 (ABAP and Java)
  • Application Server ABAP 7.51 
  • Application Server ABAP 7.52 

Why should you switch from SAP Kernel 753 to 754 ?

Previous kernels which supported the above-mentioned SAP NetWeaver and SAP Application Server ABAP stacks have gone out of maintenance. The last such SAP kernel was 749 which went out of SAP maintenance at the end of 2022. For the remaining 753 kernel, SAP plans the end of maintenance for end of 2025. 
The new 754 kernel has a much longer planned lifetime. Its planned end of maintenance date is 12/2030.

For details see  SAP Note 1969546 - Release Roadmap for Kernel 74x and 75x  (requires SAP login)

What are the specific benefits of SAP Kernel 754 on AIX ?

On AIX, the SAP kernel 754 was built with a newer compiler which is able to exploit current IBM POWER processor instructions. As a result, you can expect to see performance improvements compared to 753 or earlier kernels in particular on POWER9 or POWER10 servers. 
Furthermore, SAP kernel 754 on AIX comes with built-in 64K page size setting for all SAP kernel executables. Especially if you did not use 64K page sizes with earlier kernel releases, you should see a nice additional performance boost.

What to watch out for ?

Please note that the 754 kernel requires newer AIX and C++ runtime levels compared to kernel 753. (for details see SAP Note 1780629 - AIX: Minimal OS Requirements for SAP Kernel). To avoid the downtime that is usually associated with the AIX update, consider using AIX Live Kernel Update. For more details on Live Kernel Update see this blog post.