KAIO vps, and bufwaits

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,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