Skip to Content
author's profile photo Former Member
Former Member

PHYS_MEMSIZE after NW04S Install


I have just installed an SCM 5.0 SR2 release on WIndows 2003 64 Bit and MS SQL 2000, with 32GB RAM and 4 processors Xeon 3.5Ghz. We have an ABAP + Java instance installed on 1 server.

looking at the memory in ST02, EM has an initial size of 512 MB, the parameter PHYS_MEMSIZE has a profile value of 512, but the default is reporting as 32766, this parameter is set in the instance profile, so must have been added by the install.

The docummentation in RZ11 says the PHYS_MEMSIZE parameter should be set as the same as the physical memory, in this case 32766.

Why does the install set PHYS_MEMSIZE as 512? no parameters have been changed yet since I have just installed SCM 5.0, I've noticed this is the same value of 512 on DEV/QA/PRD SCM 5.0, each server having different actual physical memory sizes.

What do you reccommend setting for parameters :



em/initial_size_MB 512 MB

em/max_size_MB 100000

abap/buffersize 150000 KB

Also, any other parameters you reccommend setting?

I am looking to tune the memory performance before releasing the landscape to the project team.

Thanks for any advice.

Add comment
10|10000 characters needed characters exceeded

1 Answer

  • Best Answer
    author's profile photo Former Member
    Former Member
    Posted on Sep 28, 2007 at 11:37 AM

    Hi ecnirp ,

    PHYS_MEMSIZE calculates and adjusts the whole memory management. This value must maintained only if the SAP instance is not permitted to use the whole work memory.

    So actually no need to maintain anything but still try following :

    In your case, you have 32 GB to be distributed to ABAP+JAVA

    You can distribute the memory as follows:

    4 GB for OS

    14 GB for ABAP ( CI+DB)--- 8.4 GB for CI and 5.6 GB for DB

    14 GB for JAVA (CI+DB)

    that means you can set PHYS_MEMSIZE to 8.4 GB.

    No need to maintain other parmeters.

    If you get any ABAP dumps related to buffersize then only change parameter

    abap/buffersize from 150000 KB to 500000 KB

    Hope this is useful



    Add comment
    10|10000 characters needed characters exceeded

    • Former Member

      Thanks for the reply Umesh.

      I raised the PHYS_MEMSIZE to 8 GB and EM initial is now 8GB. Also changed abap/buffersize to 300000 KB, we have plenty of memory so want to limit swaps.

      I noticed the instance starts faster now, so the parameters helped.

      I'm used to the 60/40 for SAP/DB memory on Unix, not used SAP on Windows or Netweaver much so was not sure on the memory requirements for the Java instance.