Re: KAIO vps, and bufwaits

In article <34DB88BE.56A3@netcomuk.co.uk>, Neil Truby <ntruby@netcomuk.co.uk> writes >I've recently moved a poorly-performing database server from a Sun Sparc >20 to a Sun E4002 with 1.5 GBytes of memory, and 2 processors. It's >running superbly now, but I'm still keen to know where my bottlenecks >are. > >onstat -g ioq consistently shows my kio VP with a maxlength of 16, That could be from when Online is booting and loading its cache with data. Try doing an onstat -z 1 hour after the server has booted then look at the stats at the end of the day, >suggesting that the system is I/O bound. In a sample output of onstat >-g ioq in "Informix Unleashed", three kio VPs are shown, but no >explanation is given on how to configure a system to use this many (if >in fact you can). > >Does anyone know how to set up extra KAIO vps? > >Also, despite having 200M of BUFFERS, onstat -p is still showing some >bufwaits. The read cache rate is above 99%, but the write remains >around 87% - the same as on the Sparc when BUFFERS was set to 50M. The >new system isn't swapping and hardly pages; do the bufwaits suggest a >further increase in BUFFERS is warranted? > >Thanks > >Neil Truby >Chase Manhattan Bank >Bournemouth, UK >neil.truby@chase.com -- David Williams Maintainer of the Informix FAQ Primary site (Beta Version) http://www.smooth1.demon.co.uk Official site http://www.iiug.org/techinfo/faq/faq_top.html I see you standin', Standin' on your own, It's such a lonely place for you, For you to be If you need a shoulder, Or if you need a friend, I'll be here standing, Until the bitter end... So don't chastise me Or think I, I mean you harm... All I ever wanted Was for you To know that I care