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Page out rate is high in HP-UX 11.31

 
gb karki
Frequent Advisor

Page out rate is high in HP-UX 11.31

Hi Expert,

Project teams are doing testing before going to production.

Having 36 GB memory and Oracle is running.

Few days before memory utilization has reached to 100 % and i have changed filecache_max to 20%.

After that memory utilization has reduced to 90 % max but Page out rate is coming in the HP Open View report.

I 'm wondering, memory is not reaching to 100% but page out rate is coming in the picture.

Can you please suggest me what are the things (parms) i have to check and changed?

Regards
GB
4 REPLIES
likid0
Honored Contributor

Re: Page out rate is high in HP-UX 11.31

You release some memory preassure, lowering even more the filecache_max, oracle is using it's own cache(sga), and it's not going to benefit(generally! exceptions exist)from having a big file cache, You can drop into the 10%-8%.

Are you using .dbf with filesystems or raw devices?.

Windows?, no thanks
Michael Steele_2
Honored Contributor

Re: Page out rate is high in HP-UX 11.31

Hi

If you're paging then your swapping out to disk and performance is going to drop.

As reported oracle uses its own buffer cache which is located in the SGA, so fooling around with the o/s's filecache_min and max probably isn't going to help, but I don't know what else is on your box.

Attach you kernel parm values, swapinfo -tam, sar -d, and other sar's, UNIX95=1 ps -ef -o vsz,pid,ppid,state,wchan | sort -rn | head -20

Need to see what you hit ratio on oracle cache is, should be 90 to 100%.

http://www.dbspecialists.com/files/presentations/buffercache.html
Support Fatherhood - Stop Family Law
Patrick Wallek
Honored Contributor

Re: Page out rate is high in HP-UX 11.31

What does 'swapinfo -tam' show? What does the 'po' column of 'vmstat' show?

Rather than trusting OV monitors, which can falsely notify, you need to verify that you actually are paging out.
Steven E. Protter
Exalted Contributor

Re: Page out rate is high in HP-UX 11.31

Shalom GB,

Obtain kmeminfo from HP support. Take a look at reducing the Kernel size.

Based on what you say however, I'd say Oracle memory use has increased a lot. Take a look at Oracle SGA's and see what can be cut there.

SEP
Steven E Protter
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