Windows Server - Memory 8 GB - SAP using only 4GB

[Former Member]

Hi

We have installed Web AS 6.40 (ABAP + J2EE) on Windows 2003 Server (Enterprise Edition). We have also activated /3gb option. However, SAP is using page file beyond 4 GB memory. System has 4 GB memory available, but SAP is not using it.

Any ideas?

Regards

Chandu

[Former Member · Accepted solution]

Hi Chandu,

In archive boot.ini set values

[operating systems]

/pae /3GB

During the intalation of the WEB AS , the SAPINST informs only 4GB memory , but pos installation set parameter PHYS_MEMSIZE in RZ10 with the required value.

Check the value parameter PHYS_MEMSIZE in RZ11 later stop/start the instance.

Felipe

[Former Member]

Are you running the 32 or 64 bit version of Windows 2003 Enterprise?

[Former Member]

32 bit version of Windows 2003 Enterprise.

Regards

Chandu

[Former Member]

How do you have your engine(s) sized up memory wise?

[Former Member]

i didn't understand your question.

[Former Member]

Ok, first does Windows "see" all 8 gig of RAM? Look in the performance tab of task manager.

[Former Member]

yes

[Former Member]

How much memory did you allowcate for the java engine(s) like your heap size?

[Former Member]

1 GB set during the installation.

[Former Member]

My main back ground is java only installs. But, some things still apply to ABAP+java. In all the ones I have done Windows will still us page files for system and DB and anything else that is not SAP.

SAP likes to load in low continuous memory. There should not be a problem like that in Win 2003 but, you may want to check note 736462 and it's side notes to make sure.

One portal that I just got done with had the same OS and memory. Until I started getting load on that server it would sit at about 4 gig being used. But, when it was in production I went as high as 7, never used the full 8.

32 bit java has a limit of 1.7 gig per engine. I put mine at 1.536 and it played better. If you one have one engine at one gig, I can see why you are not seeing memory being used up. The ABAP side is not going to take up that much either. I think you page file is coming all from the Windows side. SAP loads into low memory and stays there.

I hope I shed some light here........

[Former Member]

Dear Dave,

I’m struggling to get a straight answer on a memory problem we’re currently experiencing and you're clearly a man who know about this subject. We’ve had a problem recently in that our servers can blue-screen when they hit 130Mb non-paged memory usage. We’ve pretty much isolated our AV software as the culprit that’s slowly eating away at this memory, as stopping AV stems the growth in non-paged memory.

We’re running with 6Gb RAM on our ECC5 application servers, and we’ve /3GB and /PAE set within boot.ini to enable Windows to allocate more addressable memory to SAP and to make use of any physical memory over 4Gb. I talked to someone yesterday who mentioned that setting /3Gb reduces the amount of non-paged memory available (from 350Mb to 250Mb – in a MS Exchange environment), but our servers are crashing at 130Mb non-paged memory, which is a bit of a mystery. I’ve asked our hosting partners to remove the /3Gb switch out of boot.ini on one of our app server to see whether this allows non-paged memory to get past 130Mb before failing.

The part that’s really confusing me though, and the part that I’m unable to get a straight answer on is /PAE. Microsoft seem to state that /PAE is required to use any RAM over 4Gb, however my most trusted BASIS advisor (been in BASIS for 12 years and has an almost unhealthy interest in it) tells me that it’s not worth setting /PAE if you’ve less than 8Gb RAM - we've only 6Gb RAM

I need to tell our hosting partners whether or not to remove /PAE at the same time as they’re removing /3Gb, but I don’t know what’s best. We’re talking ECC5 application servers here, not database servers of LiveCache.

Can you help?

Thanks

Arwel.

[Former Member]

What version of Windows are you running on what processors? Yes, it may matter.

What version of AV software are you running that is leaking like that?

Are you running a java stack on this machine too?

[Former Member]

Do not use the /3gb switch.

Use the /PAE and this will give you the access to the RAM to and above 4 gig.

[Former Member]

Hi

Thanks for the response.

I have already set /3GB /PAE in boot.ini. This did not work.

This being a Enterprise Server edition /PAE switch was already set in boot.ini and I added /3gb.

Are you sure that /PAE will solve the problem?

Regards

Chandu

Message was edited by: Chandu Cheeti

[Former Member]

That is what I have on my one portal, /PAE and that is it.

[Former Member]

Hi

I tried with only /PAE and with /PAE /3gb, no joy. I also increased PHYS_MEMSIZE. It's still using page file.

Anything else do you think of?

Regards

Chandu