Basis and others: Note 146289 - Parameter Recommendations for 64-Bit SAP Kernel

Summary

Symptom
The 64-Bit-Kernel for your SAP system has been implemented. The SAP profile parameters must be adjusted.
Other terms
64-bit kernel, 64 bit, performance, platform-id
Reason and Prerequisites
For general recommendations on the configuration of R/3 on large servers(servers with more than 2 GByte of RAM), see R/3 Notes
146528 "Configuration of R/3 on hosts with much RAM".
425207 "SAP memory management, current parameter ranges",
445533 "Lots of extended memory on AIX (64 bit)" and
789477 "Large extended memory on AIX (64-bit) as of kernel 6.20"

For SAP profile parameters that are not covered by this note, please refer to R/3 note 103747.
Availability and Implementation of the 64-bit kernel
See SAP Service Marketplace:
http://service.sap.com/platforms or Note 146528

Note that the implementation of the 64-Bit-Kernel must be tested in a test system before implementing the kernel on the production system.

Change log:

   7.3.1999: First version
  19.4.1999: Questions & Answers
  25.5.1999: Comment on Swap Space
  28.6.1999: 64-bit kernel for R/3 4.5 on HP-UX
  22.9.1999: Reference to R/3 Note 172747 (HP-UX OS parameters) added
  16.6.2000: References to SAP Notes on COMPAQ Tru64-Unix added
  10.7.2001: Note on DB2 UDB for Unix
  25.5.2002: AIX: ES/SHM_USER_COUNT, ES/SHM_SEG_COUNT, AIX DATA segment
  26.8.2004: Add platform-ID for Windows, HP-UX and Linux
15.11.2004: AIX: Reference to R/3 note 789477 added
24.02.2005: Add further platform IDs and AIX parameters
12.09.2005: AIX: abap/heap_area_* limits changed
09.12.2010: Add platform-ID for OS400 (IBM i)
Solution

1. When implementing the 64-bit kernel, we recommend at least 20 GByte of swap space. (Plus approx.10 GB for every additional 64-bit instance on the same computer) See note 153641 for more information.

2. There are no restriction or shared memory, so all buffers sizes can be set very generously (see recommendations for category III in SAP note 103747).

3. Implement the SAP profile parameters as follows:                em/initial_size_MB      1024 up to 1TB (note 835474)
    em/blocksize_KB        2048, 4096 or 8192 (note 835474)
    ztta/roll_first        1
    ztta/roll_area          6500000
           The deafult value of the following parameters is 2000000000 (2GB). They can be changed depending on the HW (RAM) and the configured SWAP Space:
               ztta/roll_extension     2000000000 (2GB)
               abap/heap_area_dia      2000000000 (2GB)
               abap/heap_area_nondia   2000000000 (2GB)
               abap/heap_area_total    2000000000 (2GB)
               See SAP Note 425207 for parameter limitations

4. For Windows 64Bit recommendations see note 88416

5. For Linux 64Bit recommendations see note 941735

6. Recommendations for HP-UX: - Important: Before setting the R/3 profile parameters, please set the HP-UX operating system parameters according to R/3 Note 172747.

7. For AIX recommendations please see the Notes provided below depending on your SAP kernel release. (see also SAP note 425207 (32-/64Bit))
             SAP Notes for          <=4.6D (64Bit)        >= 6.20 (64Bit) ---------------------------------------------------------------
                            445533                 789477
           - On AIX level: Set Soft DATA segment size and Hard DATA segment size to-1 (see SAP Note 323816).

Question & Answers

1. When shall I use the 64-bit kernel ? The following check list provides a guideline:

a) The usage of the 64-bit kernel makes sense for application servers with more than 2 GByte RAM

b) There must be 20 GByte swap space available.

c) You must have a development/test system where you can install the 64-bit kernel first.

2. Is is possible to use 64-Bit database software with 32-bit SAP kernel and vice versa?

a) For Oracle and Informix, you can use a 64-bit database software together with 64-bit SAP kernel or 32-bit SAP kernel. (You cannot use 32-Bit DB releases Oracle or Informix with the 64-Bit SAP kernel).

b) For DB2 UDB for Unix, you have to use 64-bit database software together with the 64-bit SAP kernel, only (or 32-bit database software together 32-bit SAP kernel). See SAP note 356828.

c) For 'IBM DB2 Universal Database for OS/390 and z/OS' (32-bit database software) you can use both, 32-bit SAP kernel (AIX, SUN, Windows... ) and 64-bit SAP kernel (AIX, SUN, Linux, ...).

d) For 'IBM DB2 for i' you always use the 64-bit SAP kernel.

3. How can I check whether a 64-bit kernel is used (if available) ?             - Choose in the menu: System -> Status
- See the field "Plattform-ID":

               Platform            32-bit                  64-bit
   ----------------------------------------------------------------
    DEC-Alpha           ---                      288
    HP-UX               272                      273, 274
     RM600               322                      323
    AIX                 320                      324
    OS400(6.40 & higher)---                      324
    OS400(6.20 & lower) ---              different numbers like
                                                  576,609 or 624
    SUN                 369                      370
    Linux  i386         387                      ---
    Linux  IA64         ---                      388
    Linux  x86_64      ---        (Note 816097) 390,
                                                  399 (old PID)
     Linux for zSeries   ---                      389
    Linux for IBM POWER ---                      391
    Windows i386        560                      ---
    Windows IA64        ---                      561
    Windows x86_64      ---                      562

Please see information about the avalilability of the R/3-Kernel in the notes under component XX-SER-SWREL.

4. How can I check whether a 64-bit version of a database is used?

a) Informix:

           Call transaction ST04 -> 'Detail analysis menu' ->
                                          'Onstat commands'
                        -> '-V print version'.
                       The output is e.g. '7.24.UC3'. For a 64-bit version, the character after the 2nd dot is an 'F', as in '7.30.FC3'.
                          (Note: The version given in the ST04 main screen (e.g. 'INFORMIX-OnLine Version 7.21C1') may be not correct, therefore use the menue path given above.)

b) Oracle (version at least 8.0.5):

             Call transaction ST04 -> 'Detail analysis menu' -> 'V$-Tables'
                        -> 'V$Version'
                       If a 64-bit version is used, the string '64-bit version' is displayed

5. Why does 64-bit SAP system need 20 GByte of Swap Space?                        Using the 64-bit kernel, R/3 can address memory much more generously.
                       The benefits are:
            - less need for error analysis
- low costs for tuning and configuration effort
- less program termination due to memory problems
- a single set of well-tested R/3 profile parameters for almost all R/3 systems.
                       On the other hand, this requires a large swap space. It is our opinion that the costs for 20 GByte Sap Space are low in comparison to the reduced time and cost for administration, consulting and support. (For running a test system you may configure less swap space.)

6. How much Extended Memory is possible with the 64-bit kernel ? Up to 32768 MB, after applying SAP Note 182067

7. Does the memory consumtion (physical memory) and/or OS paging increase after applying the parameter recommendations in this note? The following issues may lead to an increased paging activity:

a) When increasing the EM block size em/blocksize_KB from 1024 to 4096: In simple words: When increasing em/blocksize_KB programs run faster because of a more efficient memory allocation. On the other hand, more EM is allocated which may lead to increased paging.

b) When increasing the EM size em/inital_size_MB: In simple words: Increasing em/inital_size_MB reduces the risk that the EM is fully used and work processes have to use PRIV memory. On the other hand, a very large EM leads to increased paging due to administration overhead (even if a large part of EM is currently not used).

c) When increasing the quotas ztta/roll_extension and/or abap/heap_area_(non)dia: When increasing the quotas for the individual user contexts, programs which previously terminated with memory shortage errors will now work on. In the first position, this is a benefit for the users. On the other hand, this may lead to increased memory consumption and thus to increased paging. This is especially true, if you have "faulty" customer-developed programs or generic query programs with an "unlimied" memory consumption in your systems.

                       In normal cases, these three issues do not have any measurable negative impact on the performance of your system. However, there is always a risk that an increased paging occurs and leads to a significant performance decrease. (The increase in paging is not linearly dependend from the increase in memory consumption. The point where paging is performance-critical depends also on the operating system and hardware and is therefore difficult to predict.)
                       If you observe a performance impact due to paging after applying the recommendations from this note, we recommend that you go back to the parameter settings that you used before (with your 32-bit kernel) but that you stay on your 64-bit kernel. As a next step, we recommend that you increase parameters step by step (perhaps on one or two instances only). In parallel, you should check for programs with a large EM consumption (T-Code ST03 -> Detailed -> Extended Memory -> Block List).

Header Data


Release Status:	Released for Customer
Released on:	23.12.2010 07:48:34
Master Language:	English
Priority:	Recommendations/additional info
Category:	Consulting
Primary Component:	SV-BO Backoffice Service Delivery
Secondary Components:	BC-CST-MM Memory Management

Affected Releases

Software Component	Release	From Release	To Release	And subsequent
SAP_APPL	40	40A	40B	X
SAP_APPL	45	45A	45B	X
SAP_APPL	46	46A	46B	X
SAP_APPL	46C	46C	46C	X
SAP_BASIS	46	46D	46D	X
SAP_BASIS	60	610	640
SAP_BASIS	70	700	700

Related Notes

Attributes

Attribute	Value
Transaction codes	DB2
Transaction codes	ST03
Transaction codes	ST04
Transaction codes	TIME

Basis and others

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Note 146289 - Parameter Recommendations for 64-Bit SAP Kernel

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