RE: Sudden drop in read cache rate - why?

Are you ever resetting statistics with onstat -z? Sounds like you are intermittently hitting a point where some value wraps back to zero causing the cache hit rate to be inaccurate. Bill > -----Original Message----- > From: owner-informix-list@iiug.org [SMTP:owner-informix-list@iiug.org] > On Behalf Of Davorin Kremenjas > Sent: Thursday, June 30, 2005 7:36 AM > To: informix-list@iiug.org > Subject: Sudden drop in read cache rate - why? > > Hello everyone. > I'm experiencing Informix behaviour that feels weird to me. > Sometimes, let's say once a week on average, read cache rate drops > suddenly. > Most of the time read cache rate is very high, around 99.7 percent. > And all > of the sudden it drops to somewhere around 50%. > Then it spends few hours reaching 95% and a day or two to get over 99% > > level. As you've already guessed, after few more days the story > repeats > itself. > It never happens with write cache rate, though. > I never experience buffer overflow, that is "onstat -p" reports ovbuff > to be > zero, so I guess I have enough buffers configured. > > Config is: IDS 9.40UC5W2 on Solaris 9, Sun Fire V480 with 2 processors > and 4 > GB RAM. > > Thanks everyone. > > sending to informix-list