Re: bufwaits

In article <lB5oLCAfuFizEwx+@smooth1.demon.co.uk>, David Williams <djw@smooth1.demon.co.uk> wrote: > > In article <5m4d3t$r5s$1@tst.hk.super.net>, Mr Cheuk Kong Lo > <cklo@news.hk.super.net> writes > >I've quite a lot of bufwait (onstat -Fp) observed under 7.22 on > >HPUX 10.20 environment, but a similar engine was setup under AIX > >didn't see that. Does anyone know why and what's the general cure > >for large bufwait? And yet, I don't have ovbuff... > > > >Chris > > I have yet to see ovbuff set however increasing BUFFERS will > decrease bufwaits. This come from the Online Performance Tuning > course I went on at Informix UK.. > > The instructor said that although ovbuff was not increasing that > adding more BUFFERS was still the correct thing to do. > > He had checked with someone in the Online Development in the UK > and they had checked the actual Online Source Code... > > -- > David Williams Bufwaits could be caused by several things. One of them is Read Ahead. Check RA_PAGES and RA_TRESHOLD values in onconfig. Check also read ahead information in the last two lines onstat -p output. Bufwaits could be caused also by high user activity, application logic etc. If you can increase BUFFERS enough, it will help, David is right. But if you can`t for any reason, try to decrease RA_xxxxx params. Regards, Miroslav Lorenc SSA Czech Republic -------------------==== Posted via Deja News ====----------------------- http://www.dejanews.com/ Search, Read, Post to Usenet