Swap space is not in use

[Former Member]

Hi Guys,

We are running SAP ECC 6.0 on RHEL 4 and Oracle 10.2.0.2. Its a distributed environement. We have 16GB physical memory woth 50GB Swap space configured. My problem is our memory is fully used but swap space is Idle, have a look

Mem: 16414304k total, 13833508k used, 2580796k free, 272204k buffers

Swap: 51380200k total, 7800k used, 51372400k free, 10456892k cached

Can u help me to find out the reason why process are not using swap space and what can be done to sort out this problem

Regards

Subhash

[hannes_kuehnemund]

Dear Subhash,

the "mem used" output includes not only the memory used by applications, but also the file system cache and memory that Linux does reserve for application which might need memory in the future. You can say, that from your memory usage maybe only one third is really used by applications and two third are only reserved. In case a new application comes up, this reserved space is made free for the new application.

The row with SWAP does show that, from your "13833508k used memory" there are "10456892k cached" ! This is normal. So basically, only 3,4GB of memory is currently used by applications, the remaining 10GB allocated, are just cached/reserved.

Thanks,

Hannes

[Former Member]

Hello Hannes,

I agree with you. But i have some doubt, related to Swap usage.In my case all the swap space are idle, so i want to know when the swap space will going to use.

1.If any program executes it should use the swap space first and then it goes to main memory.

2. We have another environment on RHEL 5 with SAP ECC 6.0 , what i have found that in this machine our swap space is usage highly rather then the physical memory.

So it is possible that a workprocess take the swap space first then it goes for main memory

Regards

Subhash

[hannes_kuehnemund]

Dear Subhash,

thank you for agreeing with me, but there is no point for agreeing, because what I've said is a fact

To answer your two arguments:

1.) Wrong, any program will use main memory. If main memory is occupied, the memory from currently idle applications will be swapped out

2.) If your system is swapping, then the memory is highly used, e.g. the work processes are used by its users very intensively

Again, it is not possible, that a process used SWAP before memory!

Thanks,

Hannes

[Former Member]

Hello Hannes,

Thanks for the knowledge. So now could you please help me to analyze the exact performence of my system according to these parameters value. Because most of the FI Transaction we are getting the runtime error TSV_TNEW_PAGE_ALLOC_FAILED.

Buffer HitRatio % Alloc. KB Freesp. KB % Free Sp. Dir. Size FreeDirEnt % Free Dir Swaps DB Accs

Nametab (NTAB) 0

Table definition 99,57 20.395 3.718 21,73 60.000 13.034 21,72 0 400.134

Field definition 99,96 104.688 14.928 14,93 60.000 45.796 76,33 11.156 27.163

Short NTAB 99,95 4.875 1.778 59,27 15.000 11.062 73,75 0 3.941

Initial records 76,45 16.875 10.800 72,00 15.000 6.728 44,85 11.426 19.701

0

program 99,97 1.200.000 17.260 1,55 300.000 269.847 89,95 10.086 123.795

CUA 99,65 10.000 324 4,03 5.000 4.384 87,68 124.431 5.754

Screen 99,83 19.531 1.583 8,55 10.000 9.293 92,93 25 7.849

Calendar 100,00 488 422 88,28 200 125 62,50 0 75

OTR 4.096 3.305 99,79 2.000 1.998 99,90 0

0

Tables 0

Generic Key 99,99 195.313 12.585 6,60 15.000 3.071 20,47 75 124.217

Single record 99,81 60.000 9.022 15,09 500 245 49,00 0 133.915

0

Export/import 90,51 40.000 5.299 16,46 20.000 11.558 57,79 415.496

Exp./ Imp. SHM 99,08 4.096 3.261 98,46 2.000 1.997 99,85 0

SAP Memory Curr.Use % CurUse[KB] MaxUse[KB] In Mem[KB] OnDisk[KB] SAPCurCach HitRatio %

Roll area 3,29 34.459 46.408 1.048.576 0 IDs 99,27

Page area 4,38 87.613 418.664 524.288 1.475.712 Statement 94,00

Extended memory 46,66 4.890.624 10.076.160 10.481.664 0 0,00

Heap memory 0 0 5.859.359 0 0,00

Regards,

Subhash

[hannes_kuehnemund]

Dear Subhash,

please check [https://service.sap.com/notes|https://service.sap.com/notes], and search for TSV_TNEW_PAGE_ALLOC_FAILE. You will find lots of references which may give you hints for your problem.

In addition to that, maybe your profile parameters abap/heap_area_dia and abap/heap_area_total are set too low.

Thanks,

Hannes

[Former Member]

Thanks a lot Hannes,

I will try to analyze these things.