Re: Informix tuning

In article <35EBF8D1.50387093@acer.de>, Kai says... > >Hi, >we have a 4 CPU, 1GB, SCO 5.0.4 machine running Informix ODS 7.20.UC3. >onstat -p shows only 74% bufwrites and 94% bufreads. The machine is>running OLTP only and uses Mylex Raid controller. How do I optimize for >the Mylex? Do the recommendations still hold (number of physical >disks=CLEANERS etc..)? > >We have following settings in $ONCONFIG: >NUMAIOVPS 4Does SCO support KAIO? In which case, activate it and reduce this to 1. >CKPTINTVL 60This is very low. The default is 300 I think, although I usually use 900. There's nothing inherently wrong in forcing a checkpoint every minute if you need to for, say, recoverability reasons, but it does mean that the amount of time in which a modified page is available for re-use before being written to disk and forced out of the cache is short. This will inevitably lower the write cacheing rates you can achieve. Neil Truby Londis Holdings London, UK