Re: DSA 7.13: VP question

In article <344BC7F9.40BCCB4E@weideneder.de>, Stefan Weideneder <stefan@weideneder.de> writes >Rob Prop wrote: >> >> Hi, >> >> 1. A client of us is upgrading his system with some extra disks. The >> problem is that 50% of the disks (2 out of 4) are only used to hold >> historical data that is almost not queried, and certainly not updated. >> How many AIO VP's should I define, 1 for every (physical) disk or only 1 > >If your machine supports KAIO I would suggest to use KAIO ( HP-UX 10.x >supports KAIO I guess ) and set the number of CLEANER threads to 2 and >NUMAIOVPS to 1.> >Generally it must be better to have less AIO-vp's than too many. > > >> for every (physical) disk that does not contain historical data. >> >> 2. An other problem we have is that the system sometimes seems to lock >> itself up. The system is for example 40% idle and if another proces is >> started it changes to 0% idle. > >If the system changes to 0% idle when you start an additional ( not an >oninit ) process, then I think either the oparating system has to >manage too many processes or the process you started needs a lot of >CPU-time. > >> The server is an HP9000-K210 1 proc. and >> Informix DSA 7.13. This machine is the application and database server. >> My guess is that with the multi-threading architecture the defined CPU >> VP (only 1 defined like mentioned in the manuals)gets less time to do >> more work if a lot of user-programs are running. Is it wise to define Yes. >> more than 1 CPU VP. The workload consists of a mix of interactive and >> batch programs. >> > >Because you do not have more CPU-time ( idle 0% ) it will not make >sense to start an additional CPU-vp. Agreed. YOu have set SINGLE_CPU_VP = 1 and MULTIPROCESSOR=N havn't you? Also make sure you have enough semaphores available in the kernel. I have seen that on Phyramid it will go to 0% idle if online can not get a semaphore it needs. >To disable Priority Aging might be a solution, but this parameter >is a critical parameter on a few platforms. >If you're sure to have a lack of CPU-time I think it's a good idea >to add two or three physical CPUs. > >> Thanks in advance, >> >> Rob Prop >> >> -- >> =============================================================== >> Rob Prop Tel. : +31-164-255300 >> Consultant Fax. : +31-164-246162 >> Informa Automatisering bv Email: rprop@concepts.nl >> Bergen op Zoom informa@pi.net >> The Netherlands Web : http://www.informa.nl >> =============================================================== > > >Bye > > >Stefan -- David Williams