Re: NUMAIOVPS setting for KAIO

Fred Krefting wrote: > > David Samuels wrote: > > > > ==========Lin-Chuan Lee, 7/29/96========== > > What is recommended setting in general ( assume on platform > > with no KAIO) ?? A Performnace tuning guide I got in class > > states 1x number of disks but I also remeber the instructor > > saying that sometimes it's better to go with 2x. > >Fred Krefting wrote: > > Chao Y. Din wrote: > > > > What if KAIO is available? Should NUMAIOVPS be 1 if KAIO is available > > regardless the number of disks? > > > Probably two at a minimum. AIO is only used for cooked devices and you > should have two per physical disk. Therefore, if all you have are raw > devices you can get by with a couple of AIO's for cooked device access. > e.g. temporary files, sort files, etc. if that access is all on one > disk; and let KAIO handle the raw. I don't belive you can totally > eleminate AIO's. Two AIO's might be enough, you will have to use onstat > to see how busy those AIO's are. If they are busy add another couple and > monitor. Nothing concrete. Thanks for the info. But what if all the queues for KAIO processes are much longer than AIO queues. Is there a way to reduce KAIO queues? Chao