High avserv on K460

[michael matherly]

K460 running 11.0,3 cpus, 3 gig memory, Raid 1, Oracle 8.1.7
Attached is the output of sar -d . On a couple of disks the avserv is in the 100-300 range. This can't be good.....

[Sridhar Bhaskarla]

Micheal,

Why are you worried about this?. It is a good thing the avserv value is far more than avwait and there is no avque. Even if you observe the
%busy it is nominal. I am not worried with these numbers. What does you %wio in sar -u say?.I expect it to be minimal and you seem to be in good shape.

Also check your sar -b (buffer) stats. If your %rcache > 90 and %wcache >80, you doing good.

Are you getting complaints from the users about system being slow? Or you are just being proactive?


-Sri

[michael matherly]

%wio between 5-20
%rcache >90
%wcache needs work 30-50!
No complaints just trying to be proactive. I knew about the %wcache but, I cannot shutdown for a couple of months.

Thank you for your reply.

[Sridhar Bhaskarla]

Obviously %avserv at 300 shows that it is taking more time to process each request. But I am not worried as long as the avqueue is not above 0.5 and the %busy is low.

Keep an eye on %busy during the most busy times and observe the avserv time that time. If you have MWA installed on your system, keep a track of "GBL_DISK_SUBSYSTEM_QUEUE" from the command /opt/perf/bin/extract. As long as the QUEUE is less than 2, you are ok, else you need to start looking at your disk subsystem.


-Sri

[Sanjay_6]

Hi Michael,

Look at the thread below for the performance tuning docs on itrc.

http://us-support.external.hp.com/iv/bin/doc.pl/sid=440065a205e98af593/screen=ivHome/?NODEID=English_SHW::WW_SW_UX_SYSADM_EN_E/Q1.7&WARP=1

Hope this helps.

thanks