We have just recently upgraded our P660 from AIX 4.3.3 to 5.1 and HA from 4.x to 5. We have been having some perfomance issues. Could someone give me a brief explanation of the "performance load" of running HA. Thanks
Are you sure that HACMP is causing your performance problems? what kind of performance problems are you seeing?
Jarrett
IBM Certified Systems Expert pSeries HACMP for AIX
IBM Certified Advanced Technical Expert for AIX 5L and pSeries
- AIX 5L Systems Administration
- AIX 5L Performance and System Tuning
- p690 Technical Support
- pSeries HACMP for AIX
Thanks for the response. What happened is that we were having issues mostly pointing to I/O and we made a change and brought up the fast cache option on our SSA. There is evidently a limit of 2 loops when using fast cache so basically we had to back off our HA since to share all the drives we needed four. So... our performance has improved which we think is related to the fast cache. But since we made two changes (came up without HA) some of our peers think it could as well been a problem with HA since that was one of the last things we changed prior to going into the perfomance hole to start with. So how do I find out what HA doing in the back ground and how that could impact performance.
If your performance increased dramatically by utilizing the fast write cache than I would think your performance problems deal more with heavy disk writes than HACMP. Is your heartbeats for HACMP configured for serial or across the SSA adapters?
Do you have vmtune properly tuned for memory?
Jarrett
IBM Certified Systems Expert pSeries HACMP for AIX
IBM Certified Advanced Technical Expert for AIX 5L and pSeries
- AIX 5L Systems Administration
- AIX 5L Performance and System Tuning
- p690 Technical Support
- pSeries HACMP for AIX
Ok... not sure if the output of the current vmstat reflects the whole picture (was this run during a slow period). You are correct in that it appears that there is a lot of cpu activity and low disk usage. Could you submit the following.
lsps -s
iostat 2
/usr/samples/kernel/vmtune (you said you might not have vmtune installed)
ps aux | head -10
What type of application are you running? database, etc...
Thanks again. I tried to find the vmtume but can't find it. How do I get it? As you guessed, we are at a slow time right now. The system supports an HL7 application interface engine. Here's the other stuff.
^C/home/hci: $ cd /usr/samples/kernel/vmtune
ksh: /usr/samples/kernel/vmtune: 0403-037 The specified path name is not a directory.
/home/hci: $ cd /usr
/usr: $ cd /samples
ksh: /samples: not found.
/usr: $ ls
CYEagent asagent es linux pub sysv
HTTPServer asagentd etc local samples tivoli
IMNSearch bin games lost+found sbin tmp
TT_DB ccs include lpd share ucb
X11R6 dict java130 lpp spool usg
adm doc jdk_base man src websm
agent.cfg docsearch lbin netscape ssa
agent.cfg.old dt lib opt swlag
aix emgrdata libarclic98_api.so perfagent sys
/usr: $ ps aux | head -10
USER PID %CPU %MEM SZ RSS TTY STAT STIME TIME COMMAND
root 516 18.8 1.0 12 22820 - A Jul 14 6209:37 wait
root 774 18.2 1.0 12 22820 - A Jul 14 6024:59 wait
root 1032 18.2 1.0 12 22820 - A Jul 14 6024:46 wait
root 1290 18.2 1.0 12 22820 - A Jul 14 6022:46 wait
hci 72820 5.6 2.0 48392 46928 - A 12:44:09 40:05 /hci/root5.3/qdx
5
hci 55256 5.0 1.0 38944 23364 - A Jul 14 1663:31 /hci/root5.3/q
dx5
hci 40036 4.8 1.0 39948 37228 - A Jul 14 1569:03 /hci/root5.3/q
/usr: $
/home/hci: $ lsps -s
Total Paging Space Percent Used
4288MB 21%
/home/hci: $ iostat 2
tty: tin tout avg-cpu: % user % sys % idle % iowait
0.0 35.5 13.3 13.5 67.8 5.3
At this point it is hard to tell exactly where your bottleneck is but I suspect that its either your IO or your memory is not tuned. You should installed bos.adt.samples fileset which will give you the vmtune option. This does not require a reboot.
Since there is about 1 Gb swapped to paging, we can help that by tuning memory with vmtune (Lower the maxmperm and minperm within vmtune). I suspect that during your slow periods, the fre column in vmstat drops dramatically but you will need to run it during the slow periods to confirm. If so, we can raise the free list with vmtune to increase the application response times.
Once you get vmtune installed, run /usr/samples/kernel/vmtune and also /usr/samples/kernel/vmtune -a
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