Re: oracle is causing high WIO

Sorry, my answer was about how to find witch processes are causing the high IO.

It's now that I read that you want to know "why oracle is causing this high WIO" ..., and it's a long story :)

Read Cary Millsap's How to Activate Extended SQL Trace (http://www.hotsos.com/e-library/abstract.php?id=29) and activate the extended sql trace for the processes you find with the command from the previous mail(prstat -m).

HTH
Dimitre Radoulov

• Original Message ----- From: Radoulov, Dimitre To: raja4list_at_yahoo.com Cc: oracle-l_at_freelists.org Sent: Monday, October 24, 2005 7:59 PM Subject: Re: oracle is causing high WIO

Try prstat -m and check the major contributors for the % of SYS mode. I *think* the kernel mode includes the IO device wait time.

/app/oracle$ prstat -m

   PID USERNAME USR SYS TRP TFL DFL LCK SLP LAT VCX ICX SCL SIG PROCESS/NLWP

 11603 oracle    56 3.3 0.0 0.0 0.0 0.0  39 1.3  1K  73  1K   0 oracle/1
 24601 oracle    11 3.6 0.0 0.0 0.0 0.0  86 0.0 160  17  6K   0 oracle/1
 24599 oracle   6.2 4.1 0.0 0.0 0.0 0.0  90 0.0 138   5  5K   0 oracle/1

HTH,
Dimitre

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