Question Re: High Memory usage by disp+work in Additional Q&A

High Memory usage by disp+work

Former Member — Fri, 08 Feb 2008 00:16:49 GMT

HI all,

We had an issue today where a couple (about 9) disp+work prossors where taking over 1.3GB or RAM each with the highest topping out at just over 2.5GB.

System:

HP RX8620 (itanium)

SAN Attached (HP EVA6000)

Win2003 SP2 IA64

32 GB RAM

8 x IA64 CPU's

SQL 2005 SP2 (IA64)

My concern here is that with all this RAM being taken up by disp+work the system started to page at a high rate which then caused my SQL instance to slow to a dragging pace which caused the application to slow as well :-s

I'm fairly new to SAP... so go easy on my 😛

Thanks in advnace,

Paul

Re: High Memory usage by disp+work

Former Member — Fri, 08 Feb 2008 01:06:35 GMT

Hi Paul,

There is a possibility that some processes in SAP which is consuming resources.

When this happens again then logon to SAP and execute SM50 transaction. Here you will monitor all processes with process ID which one is causing hign load.

Hope this will help.

-Pinkle

Re: High Memory usage by disp+work

Former Member — Fri, 08 Feb 2008 08:59:48 GMT

Hi Pinkle,

Thanks for that!!

Is there anyway of looking at this data in the past tense? I can see high memory usage by looking at the permon counter that I was running at the time, but is there a way to see this in SAP?

Thanks again,

Paul

Re: High Memory usage by disp+work

Former Member — Fri, 08 Feb 2008 10:39:25 GMT

Hi Paul,

You can use ST02, ST04, ST06, ST03N transaction codes to view the performance of SAP.

ST06 will show you the past memory usage.

-Pinkle

Re: High Memory usage by disp+work

Former Member — Fri, 08 Feb 2008 10:54:33 GMT

Thanks Pinkle

Re: High Memory usage by disp+work

Former Member — Fri, 08 Feb 2008 13:14:10 GMT

Hi,

2.5 GB does not seem so high on a 32 GB Itanium Host.

We ahave had the same issue on a 16 GB itanium server because the memory quotas were not correctly defined.

We have now limited the heap memory quota to 4 GB per process which means we get a memory short dump after 2GB in extended memory + 4GB of heap memory.

We have also limited the number of processes in private mode.

The system runs now OK and is protected from heavy swapping.

Regards,

Olivier

Re: High Memory usage by disp+work

Former Member — Wed, 05 Mar 2008 17:28:34 GMT

You can go to transaction

ST02 --> double click on extended memory --> mode list

From there you see a history of which users were using all of your extended memory, and how much memory total.

Russell Hull

Re: High Memory usage by disp+work

Former Member — Mon, 24 Mar 2008 23:50:40 GMT

The issue here is you cannot trust the memory usage statistics you see at the OS level for work processes. They include shared memory areas so there is much replication of memory allocation.

Go to ST02 - Detailed Analysis - Storage for an idea of what is used and add to that the DB memory size if on the same box and also say 1GB for OS and associated memory grazers

Re: High Memory usage by disp+work

Former Member — Tue, 25 Mar 2008 08:32:07 GMT

Thank you all for your help on this one !!!

Re: High Memory usage by disp+work

Former Member — Tue, 29 Apr 2008 11:58:23 GMT

Hi Russell,

Thank you for giving good information, after checking users used extended memory what action has to be take and give some clear information i mean that what is maximum memory use can occupy