Re: AIO VP's -how many?

From: CKGeier@nwc.edu > >We are using AIX 4.3.3, and IDS 7.31UC3, with 2 processors but >MULTIPROCESSOR=0, so we are using one CPU VP. I have 2 AIO VP's >configured. We are not using kaio as it caused Informix crashes when we >implemented a web server to access the Informix database. > >I have heard differing ideas about how to configure AIO VP's. I have >looked at "onstat -g ioq" which shows me quite consistently an aio len of >0 and maxlen of 1. One book I have read, "Informix Performance Tuning" by >Elizabeth Suto says to use this command to see if there are many requests >in the aio queue. So my results seem to suggest that it probably isn't >necessary to add more aio vp's. However, I have also heard that I should >look at "onstat -g iov" and look at io/s and ours shows around 30 - this >would suggest that we should have more than 2 AIO VP's. > >AND I have also read in other books that the number of AIO VP's should be >equal to the same number of CPU VP's (one) > >AND I have also read in more books that AIO VP's should be equal to the >number of disks that I/O is being performed on. That seems to suggest we >should be using 6 of them. > >SO.....the truth is out there......Do you know how I find it or what it >is? I just keep adding AIO VPs until there's one with less than 1 io/wup in my onstat -g iov output. ________________________________________________________________________Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com