Memory release issue in AIX

[Former Member]

Hi All,

We are running our SAP applications on AIX 5.2. We have 3 applications(R/3, CRM & BW) running on one AIX host. Our DB is running on a seperate host. We have 62GB RAM in the application server.

The sum of the RollPagingExtended+Heap memory on all three applications together comes to 10GB. But in ST06 we find only 2GB free at any point in time. Is it beacuse ST06 is not getting updated or is there any other process consuming this memory. How can I see the actual memory consumption of my application.

[former_member252039]

Thanks Mark.

I also want to know AIX EM Disclaiming(SAP Note 856848, 912425 & 789477) and the critirea to set up extended memory parameter in the server. But I would close this query answered and open a new one.

Bhavik & Mark Thanks Again.

[former_member252039]

Cool. I wish I get to know those parameters. Below is the output of command vmastat -v

vmstat -v

15925248 memory pages

15366645 lruable pages

538525 free pages

8 memory pools

2480921 pinned pages

80.1 maxpin percentage

3.0 minperm percentage

90.0 maxperm percentage

11.0 numperm percentage

1703887 file pages

0.0 compressed percentage

0 compressed pages

12.0 numclient percentage

90.0 maxclient percentage

1846656 client pages

0 remote pageouts scheduled

0 pending disk I/Os blocked with no pbuf

10443616 paging space I/Os blocked with no psbuf

2740 filesystem I/Os blocked with no fsbuf

0 client filesystem I/Os blocked with no fsbuf

22827648 external pager filesystem I/Os blocked with no fsbuf

[Former Member]

Hi,

These are mine.....Tho I am not a bonafide Unix Administrator and I would recommend you have a chat with one.

Also they go against the grain form the SAP note but these are working for me.

Notice my max client %'s are low....Have a play in Dev and do some testing but I have some high volume systems working well.

All the best

Mark

vmstat -v

1572864 memory pages

1505874 lruable pages

81945 free pages

6 memory pools

309976 pinned pages

80.0 maxpin percentage

5.0 minperm percentage

8.0 maxperm percentage

7.6 numperm percentage

114654 file pages

0.0 compressed percentage

0 compressed pages

7.6 numclient percentage

8.0 maxclient percentage

114649 client pages

0 remote pageouts scheduled

0 pending disk I/Os blocked with no pbuf

44824 paging space I/Os blocked with no psbuf

2484 filesystem I/Os blocked with no fsbuf

141374 client filesystem I/Os blocked with no fsbuf

0 external pager filesystem I/Os blocked with no fsbuf

0 Virtualized Partition Memory Page Faults

0.00 Time resolving virtualized partition memory page faults

[former_member252039]

Hi Mark,

In st06 it is currently showing 2.16 GB free. I was under the impression that this was not changing becuse there was a problem with the SAPOSCOL program. But looks like it is changing. Adding up the (Roll + Extended +Paging +heap) for all three applications it is currently using 33 GB. How do I find the remaining memory distribution?

Thanks

[Former Member]

Hi,

I have found this note : 973227......Now it conflicts a little with what I have been saying but I would be interested what your

output from vmstat -v looks like.

From my experience when we migrated from HP to AIX many moons ago we had an issue where the SAP application was short of memory although we had oodles of it and came down to some filesystem caching (% client) we changed the OS parameter and the memory re-appeared inST06 as free memory without detriment to the overall performance....

Mark

[former_member252039]

Hi Mark,

Below is the figure.

PAGING SPACE

Size,MB 40960

% Used 55.6

% Free 44.3

MEMORY

% Comp 85.8

% Noncomp 11.1

% Client 12.0

What do we infer from the %Noncomp & Client% ?

Does it mean that my system is currently utilising 85% total RAM?

Thanks

[Former Member]

Hi,

Does it mean that my system is currently utilising 85% total RAM?

Yes the AIX partition is using 85% of the Memory

What do we infer from the %Noncomp & Client% ?

These percentages are high and this is memory that should be availble to SAP. It's been few years

but there is some OS cache going on the does not need to be. I will try to find the OS command to switch off.

Try a man topas fo info

In ST06 what of your 62GB RAM, what is you free space ?

Mark

[former_member252039]

Hi Bhavik,

Thanks for your reply. I have 3 applications SAR R/3 Enterprise 4.7, CRM 4.0 & BW 3.5. Kernal release would be 640 patch level 175. The kernal or the SAPOSCOL is not the latest. It is pretty old version. There is no problem with the permission or ownership. I believe the SAPOSCOL would not start if it is not the case ? Should I update just the SAPOSCOL program or update the latest SAPEXE and SAPEXDEDB to the latest version?

Another thing I find is when I monitor from Topas, we see that the Paging % used is gone up to 55% and it is not coming down even when there is no paging hapening in the system.

Regarding monitoring memory

[Former Member]

Hi,

what is yor PAGE SPACE size ?

and what is your

% non comp

% client

values in TOPAS

Mark

[former_member524429]

Hi,

Release level of Installed SAP Applications ?

SAP Kernel release & patch level per SAP Applications ?

Are you facing any memory related issues on any SAP Application ?

The Data which is displayed in ST06 are collected by SAPOSCOL process at OS level. Does the version of SAPOSCOL in use is the latest ? You can download the latest one and install it according to SAP Note 710975 and 19227.

Check whether saposcol belongs to user 'root' and whether the authorizations are correct: -rwsr-x---

Because the values of saposcol must be visible for all R/3 systems/instances on a host. Please refer SAP Note 189072.

How can I see the actual memory consumption of my application.

You can analyze RES (Resident Memory Size per process) column per <SID>adm user in the output of top command. Also you can use Third Party utility such as Manage-Engine Application Manager to have more detailed information.

Regards,

Bhavik G. Shroff