Latest Set of General Purpose AIX v5.3 Tunables
Please ensure you test these first before implementing in production as your mileage may vary
Network
no -p -o rfc1323=1
no -p -o sb_max=1310720
no -p -o tcp_sendspace=262144
no -p -o tcp_recvspace=262144
no -p -o udp_sendspace=65536
no -p -o udp_recvspace=655360
nfso -p -o rfc_1323=1
nfso -p -o nfs_socketsize=600000
nfso -p -o nfs_tcp_socketsize=600000
Memory Settings
vmo -p -o minperm%=5
vmo -p -o maxperm%=90
vmo -p -o maxclient%=90
vmo -p -o minfree=1000
vmo -p -o maxfree=1200
vmo -p -o lru_file_repage=0
vmo -p -o lru_poll_interval=10
Leave strict_maxperm and strict_maxclient at their defaults
IO Settings
Leave minpgahead and J2_minPageReadAhead at their defaults of 2
ioo -p -o j2_maxPageReadAhead=128
ioo -p -o maxpgahead=16
ioo -p -o j2_nBufferPerPagerDevice=1024
ioo -p -o hd_pbuf_cnt=1024
ioo -p -o numfsbufs=2048
ioo -p -o pv_min_pbuf=1024
#### this is the 5.3 value - below is the one for 5.2
### ioo -p -o pv_min_pbuf=1024
If doing lots of raw I/O you may want to change lvm_bufcnt
Default is 9
ioo -p -o lvm_bufcnt=12
Others left to default that you may want to tweak include:
ioo -p -o numclust=1
ioo -p -o j2_nRandomCluster=0
ioo -p -o j2_nPagesPerWriteBehindCluster=32
ioo -p -o j2_maxRandomWrite=32
ioo -p -o maxrandwrt=32
These are starting points only
Other areas to look at tuning:
Fiber cards
Check out max_xfer_size - 0x100000 is 16mb dma, 0x200000 is 128mb dma
For heavy I/O you may want to change this to 128mb
hdisks
Check out queue_depth. If seeing sqfull on iostat -D then
increase queue_depth if your disk subsystem allows it
posted at: 09:48 | path: | permanent link to this entry
2/8/2007 AIX v5.3 Links to get perfscript and instructions
Script to gather data
http://www.circle4.com/jaqui/perfdata53-latest.sh.txt
Instructions for script and nmon
http://www.circle4.com/jaqui/perf-script-instructions.txt
posted at: 18:18 | path: | permanent link to this entry
2/8/2007 AIX v5.3 Tunables Update
When making tunable changes please be sure to test them first.
1. Please be careful when setting lru_file_repage. If you are asked to change this value
from the default (which you should) please ensure you first set maxperm and maxclient back to 80%
2. I do want to mention that a couple of the parameters may not work well with certain workloads, specifically maxrandwrt and maxpgahead. The situation where I saw a problem was very application specific (Topform and Providex) but try it both ways.
I normally set them for JFS and JFS2 as follows:
ioo -p -o j2_maxPageReadAhead=128
ioo -p -o maxpgahead=16
ioo -p -o j2_maxRandomWrite=32
ioo -p -o maxrandwrt=32
However, you may be better to leave them at the defaults:
ioo -p -o j2_maxPageReadAhead=128
ioo -p -o maxpgahead=8
ioo -p -o j2_maxRandomWrite=0
ioo -p -o maxrandwrt=0
posted at: 18:07 | path: | permanent link to this entry
2/8/2007 General Purpose AIX v5.2 at >ML4 Tunables
Current recommended AIX v5.2 ML4 Performance Parameters:
Please ensure you test these first before implementing in production as your mileage may vary
Network
no -p -o rfc1323=1
no -p -o sb_max=1310720
no -p -o tcp_sendspace=262144
no -p -o tcp_recvspace=262144
no -p -o udp_sendspace=65536
no -p -o udp_recvspace=655360
nfso -p -o rfc_1323=1
nfso -p -o nfs_socketsize=600000
nfso -p -o nfs_tcp_socketsize=600000
Memory Settings
vmo -p -o minperm%=5
Leave maxperm and maxclient at default of 80
Leave strict_maxperm and strict_maxclient at their defaults
vmo -p -o minfree=960
vmo -p -o maxfree=1088
vmo -p -o lru_file_repage=0
vmo -p -o lru_poll_interval=10
IO Settings
Leave minpgahead and J2_minPageReadAhead at their defaults of 2
ioo -p -o j2_maxPageReadAhead=128
ioo -p -o maxpgahead=16
ioo -p -o j2_maxRandomWrite=32
ioo -p -o maxrandwrt=32
ioo -p -o j2_nBufferPerPagerDevice=1024
ioo -p -o hd_pbuf_cnt=1024
#### this is the 5.3 value - above is the one for 5.2
### ioo -p -o pv_min_pbuf=1024
ioo -p -o numfsbufs=2048
If doing lots of raw I/O you may want to change lvm_bufcnt
Default is 9
ioo -p -o lvm_bufcnt=12
Others left to default that you may want to tweak include:
ioo -p -o numclust=1
ioo -p -o j2_nRandomCluster=0
ioo -p -o j2_nPagesPerWriteBehindCluster=32
These are starting points only
posted at: 18:06 | path: | permanent link to this entry
2/8/2007 General Purpose AIX v5.3 Tunables
Current recommended AIX v5.3 Performance Parameters:
Please ensure you test these first before implementing in production as your mileage may vary
Network
no -p -o rfc1323=1
no -p -o sb_max=1310720
no -p -o tcp_sendspace=262144
no -p -o tcp_recvspace=262144
no -p -o udp_sendspace=65536
no -p -o udp_recvspace=655360
nfso -p -o rfc_1323=1
nfso -p -o nfs_socketsize=600000
nfso -p -o nfs_tcp_socketsize=600000
Memory Settings
vmo -p -o minperm%=5
Leave maxperm and maxclient at default of 80
Leave strict_maxperm and strict_maxclient at their defaults
vmo -p -o minfree=960
vmo -p -o maxfree=1088
vmo -p -o lru_file_repage=0
vmo -p -o lru_poll_interval=10
IO Settings
Leave minpgahead and J2_minPageReadAhead at their defaults of 2
ioo -p -o j2_maxPageReadAhead=128
ioo -p -o maxpgahead=16
ioo -p -o j2_maxRandomWrite=32
ioo -p -o maxrandwrt=32
ioo -p -o j2_nBufferPerPagerDevice=1024
ioo -p -o pv_min_pbuf=1024
ioo -p -o numfsbufs=2048
If doing lots of raw I/O you may want to change lvm_bufcnt
Default is 9
ioo -p -o lvm_bufcnt=12
Others left to default that you may want to tweak include:
ioo -p -o numclust=1
ioo -p -o j2_nRandomCluster=0
ioo -p -o j2_nPagesPerWriteBehindCluster=32
These are starting points only
posted at: 17:35 | path: | permanent link to this entry
Using and Obtaining nmon
Nmon is available for AIX and Linux (x86 and Power)
Download the latest nmon for AIX v5.3 from
http://www-941.ibm.com/collaboration/wiki/display/WikiPtype/nmon
You will need to gunzip it and untar it
I untar it to /usr/local/perf
Then run nmon_aix53 as follows:
cd /usr/local/perf
nmon_aix53 -fT -c 30 -s 240
This will cause nmon to run for about 2 hours gathering data - the output will be put in /usr/local/perf
Once it is finished (check using ps -ef | grep nmon) then use nmon analyzer and MS Excel to analyze the output
nmon analyser can be found at:
http://www-128.ibm.com/developerworks/eserver/articles/nmon_analyser/index.html
or
http://www-941.haw.ibm.com/collaboration/wiki/display/WikiPtype/nmonanalyser
You can find out more about nmon at Nigel Griffiths' online workshop at:
http://www-941.ibm.com/collaboration/wiki/display/WikiPtype/nmon+Introduction+Workshop
posted at: 22:07 | path: | permanent link to this entryWed, 19 Apr 2006
Welcome to my Blog. As I have time I will put updates on various technical issues here for you to check out. If you have questions, feel free to email me and I will either answer them here or I will answer them via my column in IBM's Systems Magazine for pSeries (used to be eServer for UNIX),
posted at: 13:43 | path: | permanent link to this entry
