Increasing Memory -- how will the SAP Profiles need to be adjusted?

[MPGraziano]

Good Morning...

We are planning to increase the Memeory on Wind2003 server running sql 2005 (64bit OS) from 32G to possibly double or triple the size.

To get the most power to SAP from the increas in memory could someone please suggest how to tweek the SAP Profiles and/or provide sapnotes , papers for reading

Kind Regards,

Maria

[anindya_bose · Accepted solution]

For SAP memory on WINDOWS you can start with SAP NOTE https://service.sap.com/sap/support/notes/88416

[MPGraziano · Accepted solution]

Thanks... we've already implemented that note on both ECC 6.0 and BI 7.0 when we migrated to 64bit OS

maria

[anindya_bose · Accepted solution]

Maria

Mostly you can tweak the below parameters if you are doubling your RAM size as mentioned in 88416.

em/initial_size_MB

em/max_size_MB

em/address_space_MB

ztta/roll_first

ztta/roll_area

ztta/roll_extension

abap/heap_area_dia

abap/heap_area_nondia

abap/heap_area_total

rdisp/ROLL_MAXFS

rdisp/ROLL_SHM

rdisp/PG_MAXFS

rdisp/PG_SHM

PHYS_MEMSIZE

You can also look for buffer parameters. If there is more number of swaps then you can revise that particular parameter.

[MPGraziano · Accepted solution]

Ok,

so if a param will turn red... than I know that it will require attention or tweeking, however the issue that gets me how do I estimate how much to increase it by?

maria

[markus_doehr2 · Accepted solution]

> so if a param will turn red... than I know that it will require attention or tweeking, however the issue that gets me how do I estimate how much to increase it by?

tuning buffers is an iterative process. It's possible to recommend a parameter based on the runtime of the system and number of swaps, however, the best values can only be found out iteratively.

I'd increase the parameter by 50 %, restart the system and watch it for a few more days, if it turns red again redo the same.

We have e. g. an abap/buffersize of 3,000,000 because we almost use all "modules" of the system. If you use on e. g. SD and MM, that buffer doesn't need to be that big.

Markus

[anindya_bose · Accepted solution]

Yes ..I would second Markus here.. Suppose your system is running since last 6 months without a restart and you see Program Buffer swap of 2000. That's may not be an issue. But if you see for 6 month there is more than 20000 swaps in case of program buffer most probably you need to tune that param. Best was to increase by 30 t0 50 percent and then wait for some days to see the effect.

If you search in Service Marketplace by "buffers st02" you will get lots of notes regarding each buffers.

you can also check the documentation of each parameter from RZ11.

Additionally you can look at note https://service.sap.com/sap/support/notes/103747.

Please also check your virtual memory size, you should increase with increase in physical memory

Edited by: Anindya Bose on Oct 20, 2009 7:37 PM

[MPGraziano · Accepted solution]

Both good input...

I'm am still pretty green when it comes to tuning, and also nervous to make changes to any of those profile params for fear of throwing another param or performance off...

[markus_doehr2]

You know what your bottleneck is? Is it the database memory or the SAP memory?

Markus

[MPGraziano]

Well, that's not a complete issue right now...

we are in the process of re-designing our landscape to include clustering, or current HW is at end of life and we cannot increase MEM on them, so we are considering purchasing new HW with additional MEM, we are not sure how much more MEM, however we will increase none the less...

I am not completly up on how to identify where bottlenecks are... That is an area I want to learn more about (tuning and trouble shooting for better performance ...)

for now IF we purchase the new HW with additional MEM, I just want to ensure that we make the most of our new acquisitions.

Thanks,

Maria