Hi,
I am new registered user here in this UNIX forums.
I am a new system administrator for AIX 6.1. One of our servers performs poorly every time our application (FINACLE) runs many processes/instances. (see below for topas snapshot)
I use NMON or Topas to monitor the server utilization. I checked the the CPU Idle% and the idle percent is high, however the DISK Busy% is constantly high (during real poor performance, the DISK Busy% is most of the time 100%). Also, I noticed that the FILE/TTY Readch and Writech are constantly high too. See topas snapshot below:
CPU User% Kern% Wait% Idle% Physc Entc
ALL 0.7 0.4 5.5 93.5 0.10 1.7
Disk Busy% KBPS TPS KB-Read KB-Writ
Total 100.0 10.8K 219.0 0.0 10.8K
FileSystem KBPS TPS KB-Read KB-Writ
Total 6.5K 648.6 3.8K 2.7K
Name PID CPU% PgSp Owner
oracle 1311046 0.6 10.6 oracle
vmmd 458766 0.2 1.2 root
aioserve 10682432 0.0 0.4 uatadm2
topas 25755848 0.0 8.9 bankadm
tnslsnr 25493548 0.0 20.4 oracle
oracle 5439982 0.0 14.7 oracle
EVENTS/QUEUES FILE/TTY
Cswitch 585 Readch 3915.9K
Syscall 2055 Writech 2759.0K
Reads 630 Rawin 0
Writes 90 Ttyout 1628
Forks 1 Igets 0
Execs 0 Namei 99
Runqueue 1.1 Dirblk 0
Waitqueue 0.5
Memory
PAGING Real,MB 43776
Faults 1639 % Comp 47
Steals 0 % Noncomp 51
PgspIn 0 % Client 51
PgspOut 0
PageIn 0 PAGING SPACE
PageOut 691 Size,MB 12288
Sios 700 % Used 1
% Free 99
NFS (calls/sec)
SerV2 0 WPAR Activ 0
CliV2 0 WPAR Total 0
SerV3 0 Press: "h"-help
CliV3 0 "q"-quit
here's our server specs:
System Model: IBM,8205-E6B
Machine Serial Number: 0678F8P
Processor Type: PowerPC_POWER7
Processor Implementation Mode: POWER 7
Processor Version: PV_7_Compat
Number Of Processors: 6
Processor Clock Speed: 3720 MHz
CPU Type: 64-bit
Kernel Type: 64-bit
LPAR Info: 2 CARD_DB
Memory Size: 43776 MB
Good Memory Size: 43776 MB
Platform Firmware level: AL720_082
Firmware Version: IBM,AL720_082
Console Login: enable
Auto Restart: true
Full Core: false
Network Information
Host Name: CARDDB
IP Address: 10.10.10.100
Sub Netmask: 255.255.255.0
Gateway: 10.10.10.10
Name Server:
Domain Name:
Paging Space Information
Total Paging Space: 12288MB
Percent Used: 1%
Volume Groups Information
==============================================================================
rootvg:
PV_NAME PV STATE TOTAL PPs FREE PPs FREE DISTRIBUTION
hdisk0 active 546 458 109..48..83..109..109
hdisk1 active 546 390 29..60..83..109..109
==============================================================================
oravg:
PV_NAME PV STATE TOTAL PPs FREE PPs FREE DISTRIBUTION
hdisk8 active 4228 68 00..00..00..00..68
==============================================================================
Everytime this happens, we try to kill processes that is CPU consuming, but still, the DISK Busy% is high. If we reboot the server, the performance becomes okay, but we can't do this during production. Any suggestion on how to optimize this? is it our architecture (having only 1 hard disk for our data)? Does bottle-necking takes place here? What can we do to optimize our server? Any upgrades shall we make? for example increasing physical memory.
Thank you very much. I hope you can help since I am not a UNIX expert.