disks in rootvg is 100% busy. users can not login GUI. Help!

[Former Member]

I have a system problem. Today, in about 20 minutes, users can not logon to the system from their GUI. I can see some information in AIX .

the system rootvg:hdisk0,hdisk1 is 100%busy.

there are many swap, pagein pageout viewing from vmstat .

another information is : In our system, the memory usage is always 90%,and the swap usage is always 25% . If I restart the system, the swap usage will be below 10%, after several weeks, it becomes 25% again.

why hdisk0,hdisk1 is busy, there are no sap data in rootvg.

if it is because we have not restart our system for a long time ?

thanks

[Former Member · Accepted solution]

hi,

you should check your OS level process on AIX. Make sure that you check which process had consummed biggest resources.

ardhian

http://sapbasis.wordpress.com

[Former Member · Accepted solution]

the cpu is not busy , and cpu wait is 40%, it is waiting the disk I/O.

[Former Member · Accepted solution]

Hi Victor,

The OS is showing heavy IO on disk0 and disk1 is because you would be having your swap volumes defined on the same.

use 'lspv -a' or swapinfo. one of them works on AIX. it will list the devices on which swap is located.

Would advice to reduce the memory allocation to SAP to prevent excessive swapping. You can check the amount of SAP memory defined by using the command 'sappfpar check pf=<instance profile>' and compare it with the physical memory available on the server.

Add Database memory to it (if database is on the same server) (sqlplus '/as sysdba' and 'show sga' at sql prompt)

Good to leave out 1 or 2 Gb of physical memory free.

Thanks and Best Regards,

Sunil.

[Former Member · Accepted solution]

oh, thanks a lot. Could you give me some advices base on the following information ;

we have 8G physical memory and 20G swap space.

KS1DSDB1:/> lsps -a

Page Space Physical Volume Volume Group Size %Used Active Auto Type

paging00 hdisk1 rootvg 15360MB 1 yes yes lv

paginglv00 hdisk0 rootvg 3072MB 1 yes yes lv

hd6 hdisk0 rootvg 2048MB 1 yes yes lv

================================================================================

== Checking profile: ./PRD_DVEBMGS00_KS1DSDB1

================================================================================

Shared memory disposition overview

================================================================

Shared memory pools

Key: 10 Pool

Size configured.....: 262000000 ( 249.9 MB)

Size min. estimated.: 256611778 ( 244.7 MB)

Advised Size........: 260000000 ( 248.0 MB)

Key: 40 Pool for database buffers

Size configured.....: 236000000 ( 225.1 MB)

Size min. estimated.: 231513792 ( 220.8 MB)

Advised Size........: 234000000 ( 223.2 MB)

Shared memories inside of pool 10

Key: 11 Size: 500000 ( 0.5 MB) Factory calender buffer

Key: 12 Size: 6000000 ( 5.7 MB) TemSe Char-Code convert Buf.

Key: 13 Size: 60500000 ( 57.7 MB) Alert Area

Key: 14 Size: 20000000 ( 19.1 MB) Presentation buffer

Key: 17 Size: 2672386 ( 2.5 MB) Roll administration

Key: 30 Size: 28672 ( 0.0 MB) Taskhandler runtime admin.

Key: 33 Size: 61440000 ( 58.6 MB) Table buffer, part.buffering

Key: 34 Size: 10240000 ( 9.8 MB) Enqueue table

Key: 51 Size: 3200000 ( 3.1 MB) Extended memory admin.

Key: 54 Size: 40968192 ( 39.1 MB) Export/Import buffer

Key: 55 Size: 8192 ( 0.0 MB) Spool local printer+joblist

Key: 57 Size: 1048576 ( 1.0 MB) Profilparameter in shared mem

Key: 58 Size: 4096 ( 0.0 MB) Enqueue ID for reset

Shared memories inside of pool 40

Key: 42 Size: 22720992 ( 21.7 MB) DB TTAB buffer

Key: 43 Size: 104303736 ( 99.5 MB) DB FTAB buffer

Key: 44 Size: 25409656 ( 24.2 MB) DB IREC buffer

Key: 45 Size: 15548536 ( 14.8 MB) DB short nametab buffer

Key: 46 Size: 20480 ( 0.0 MB) DB sync table

Key: 47 Size: 10241024 ( 9.8 MB) DB CUA buffer

Key: 48 Size: 300000 ( 0.3 MB) Number range buffer

Key: 49 Size: 2968344 ( 2.8 MB) Spool admin (SpoolWP+DiaWP)

Shared memories outside of pools

Key: 1 Size: 2500 ( 0.0 MB) System administration

Key: 2 Size: 37759904 ( 36.0 MB) Disp. administration tables

Key: 3 Size: 114048000 ( 108.8 MB) Disp. communication areas

Key: 4 Size: 518248 ( 0.5 MB) statistic area

Key: 6 Size: 851968000 ( 812.5 MB) ABAP program buffer

Key: 7 Size: 14838 ( 0.0 MB) Update task administration

Key: 8 Size: 134217828 ( 128.0 MB) Paging buffer

Key: 9 Size: 268435556 ( 256.0 MB) Roll buffer

Key: 16 Size: 22400 ( 0.0 MB) Semaphore activity monitoring

Key: 18 Size: 917604 ( 0.9 MB) Paging adminitration

Key: 19 Size: 100000000 ( 95.4 MB) Table-buffer

Key: 31 Size: 4806000 ( 4.6 MB) Dispatcher request queue

Key: 41 Size: 25010000 ( 23.9 MB) DB statistics buffer

Key: 52 Size: 40000 ( 0.0 MB) Message Server buffer

Key: 62 Size: 85983232 ( 82.0 MB) Memory pipes

Key: 63 Size: 409600 ( 0.4 MB) ICMAN shared memory

Key: 64 Size: 4202496 ( 4.0 MB) Online Text Repository Buf.

Key: 65 Size: 4202496 ( 4.0 MB) Export/Import Shared Memory

Key: 1002 Size: 400000 ( 0.4 MB) Performance monitoring V01.0

Key: 58900100 Size: 4096 ( 0.0 MB) SCSA area

Nr of operating system shared memory segments: 22

Shared memory resource requirements estimated

================================================================

Nr of shared memory descriptors required for

Extended Memory Management (unnamed mapped file).: 8

Total Nr of shared segments required.....: 30

System-imposed number of shared memories.: 1000

Shared memory segment size required min..: 851968000 ( 812.5 MB)

System-imposed maximum segment size......: 35184372088832 (33554432.0 MB)

Swap space requirements estimated

================================================

Shared memory....................: 2030.3 MB

..in pool 10 244.7 MB, 97% used

..in pool 40 220.8 MB, 98% used

..not in pool: 1557.3 MB

Processes........................: 362.3 MB

Extended Memory .................: 4096.0 MB

-

---

Total, minimum requirement.......: 6488.6 MB

Process local heaps, worst case..: 1908.0 MB

Total, worst case requirement....: 8396.6 MB

Errors detected..................: 0

Warnings detected................: 0

============================================================================================

SQL> show sga

Total System Global Area 3172963096 bytes

Fixed Size 746264 bytes

Variable Size 1107296256 bytes

Database Buffers 2063597568 bytes

Redo Buffers 1323008 bytes

Edited by: victor on Oct 19, 2008 3:35 AM

[Former Member · Accepted solution]

Hello,

If you total shared memory requirements of your SAP system Oracle SGA + Extended Memory + SAP Buffers + Other OS programs is higher than your total physical memory. Hence the paging will always happen. If you wish to reduce paging use any of the 2 options;

1. Reduce the shared memory allocation for SAP and Oracle ( SGA, program buffers etc..)

2. Add more physical memory to the box.

Regards,

Manoj