Re: How much Memory for Informix

In article <D54B3n.GDy@cix.compulink.co.uk>, tbone@cix.compulink.co.uk ("Chris Totten") says: > >We have to do a sizing job on a system we are about to install and need a >view on how much memory we should recommend per user. The system is >running Informix RDS runtime with Informix SE engine on a HP9000 box. > We supply a system using RDS & SE, where there is a 'startup' menu program in 4GL from which the users load other programs. Some of the most commonly programs are very large (don't ask why!), and we have found that 2MB per user seems to be adequate - mostly the platforms are ICL DRS6000 or Motorola S900. 'sar' can be used to see if there is some memory left. If there is not enough memory, the system will start 'thrashing' e.g. the CPU will spend most of it's time swapping & paging which shows as high %sys, low %user, and zero %wio and %idle in 'sar'. Remember also to configure enough swap space, in evanly sized slices across all spindles if possible. Allow 2-3 times memory. Hope this helps. It's based on experience. We couldn't get Informix to way anything beyond 'well. It all depends!' Sally