Re: tuning BUFFERS

>I'm currently tuning the BUFFERS parameter. I've read that if you increase >BUFFERS too much that the operating system will start swapping which will >kill your performance. How will I know if this is happening? I'm running >IDS 7.22 on HPUX 10.20. > >Thanks I know nothing about Informix but since this seems to be more of a HP-UX question with some trepidation I will (foolishly) attempt to answer your question. To check for swap thrashing on HP-UX 10.20: " Check swapinfo -tm . In swapinfo -tm, you'll see the swapspace usage which gives you an idea of just how many megs are going for swap (ignore reserve since this is just preallocated, not actually in use). Also use sar -w 1 5 and see what the context switch rate and blocks per second for swap out (ignore swap in as this also counts program starts). Multi-digit numbers (20-50 or higher) indicate swap thrashing (not enough RAM)." This advice is from Bill Hassell of HPUX-ADMIN list fame. You may want to check out the archives at: http://www.dutchworks.nl/htbin/hpsysadmin It would also be an idea to use GlancePlus so you can see what's happening as it happens. Of course even if swapinfo or sar indicate that you have memory thrashing that will not necessarily tell you anything about what you should set BUFFERS to. I leave the topic of tuning the BUFFERS parameter to the real experts. Good luck, Michael Martin michael_martin@komatsu.co.jp