Re: System tuning

In article <4ivh5r$guu@cssun.mathcs.emory.edu>, Informix Sysadmin <informix@asl3.asl-labs.bc.ca> wrote: > >This is on a system that has between 20-35 informix users, 128Mb RAM, >2x88100 CPU's running DG/UX5.4R3.10 The database is on 5x1Gb RAID5 >disks. Does it seem immediately obvious to anyone as to what we might be >missing here? Our system DOES NOT run as fast as it did with 5.x Our >users aren't terribly happy these days :( We recently encountered similar sounding performance problems using Informix 7.11UC2X?? on a HP K400 with 2 processors and 1280M (!) of RAM. We had almost 99% cache hits, with still extremely sluggish performance. Our final performance tuning victory came after playing with the NUMCPUVPS, MULTIPROCESSOR, and SINGLE_CPU_VP parameters in the onconfig file. MULTIPROCESSOR 0 NUMCPUVPS 1 SINGLE_CPU_VP 1 gave us stunning performance gains. The manual (in the very fine print) affirms that this is the way to configure our system with two CPUs even though the MULTIPROCESSOR 0 sounds a little funny at first. Informix attributes this to the fact that with a single CPUVP, the whole mutexing/latching/locking scheme is dramatically reduced in complexity. Best of luck... Jon McNeill (415) 802-4956 Systems Integration Consultant jmcneill@us.dhl.com Andersen Consulting