RE: Concurrent I/O (AIX 5.2)

I second that recommendation - we have done that here as well. But I wouldn't say that *alone* is where I would start - there are several other critical factors that must be considered as well, as I previously mentioned: increasing db_cache_size to compensate for the buffering you're taking away from AIX, setting agblksize=512 for redologs to align the block size with size of Oracle's I/O requests (otherswise it reverts back to regular buffered I/O regardless of your CIO settings), and mounting the filesystems with o=cio if you're on 9i (not necessary in 10g). We also increased minservers and maxservers - and implemented the SGA in large pages (16MB) and pinned them in memory (lock_sga=true & v_pinshm=1).

From: oracle-l-bounce_at_freelists.org
[mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Gene Sais Sent: Thursday, June 29, 2006 5:08 AM
To: oracle-l_at_freelists.org; Stuart Clowes Subject: Re: Concurrent I/O (AIX 5.2)

Have you looked at vmo parameters that affect page stealing. I have mine set to:  

vmo -p -o minperm%=5            # Was 20
vmo -p -o maxclient%=10         # Was 80
vmo -p -o maxperm%=10           # Was 80

This alone is the first place I would start.

Privileged/Confidential Information may be contained in this message or attachments hereto. Please advise immediately if you or your employer do not consent to Internet email for messages of this kind. Opinions, conclusions and other information in this message that do not relate to the official business of this company shall be understood as neither given nor endorsed by it.

--
http://www.freelists.org/webpage/oracle-l