Re: SCO Unix and Informix 7 Performance

Kai Shen wrote: > > Hi all, > > we are currently running SCO OS 5.0.2 and Informix OL 7.11, the machine > is a double Pentium Pro/200 with 512 MB RAM, 4 harddisks with 14 GB > (plus duplexed). The system is mainly used as OLTP (80%), our onconfig > says: > MULTIPROCESSOR 1 NUMCPUVPS 1 LOCKS 300000 > BUFFERS 50000 NUMAIOVPS 4 PHYSBUFF 1024 > LOGBUFF 256 CLEANERS 4 SHMTOTAL 0> CKPINTVL 300 LRUS 8 LRU_MAX_DIRTY 2 > LRU_MIN_DIRTY 1 LTXHWM 50 LTXEHWM 60> OPTCOMPIND 0 AFF_SPROC 0 AFF_NPROCS 2 > NOAGE 0 > (Any other?)> > We experience much less performance compared to our previous system > (single P166 cpu, 256 MB RAM, Online 6.0) > > The duplexing is handled by the OS and therefore I believe the > additional hard disks should not be taken into account, concerning > NUMAIOVPS, correct? > > We have a tool monitoring the CPU utilization, which says 100% for the > first CPU and almost nothing for the second. Is there a way to balance > the CPU load to both CPUs dynamically? Which parameters should be tuned? > Which other parameters seem to create bottlenecks? > > Please please help me! Any ideas appreciated. > > TIA > > Regards, Kai Hi Kai, Because you are using only 2 processors, I would suggest to start only 1 CPU-vp, switch MULTIPROCESSOR off and turn on SINGLE_CPU_VP. I think these settings will match with your earlier settings. Switch MULTIPROCESSOR to 1 if you have at least 4 physical processors. In your current configuration there's a mismatch between the number of CPU-vp's (1) and the binding of CPU-vp's to physical processors (2). If you made the changes and still get a poor performance, please have a look at the "wait-statistics" of your OnLine instance. If the statistics show a CPU bottleneck ( mt-ready waits dominate ), then you might start two additional CPU-vp's ( in this case you must switch off SINGLE_CPU_VP and set NUMCPUVPS to 3 or more ). Bye Stefan