Re: Question about KAIO

ccremid wrote: > > Informix gurus: > > Basic Information: On-line 7.23UC1, AIX 4.2 , 1 CPU > > Can some one explain the output of onstat -g ioq. Specifically the > lines that refer to kio. I have two servers with similar configuration, > but when I run the onstat command I got the following output. > > INFORMIX-OnLine Version 7.23.UC1 -- On-Line -- Up 1 days 23:59:29 -- > 27120 Kbytes > > AIO I/O queues: > q name/id len maxlen totalops dskread dskwrite dskcopy > kio 0 0 0 0 0 0 0 > kio 1 0 32 696237 682454 13783 0 > [ ....] > > and > INFORMIX-OnLine Version 7.23.UC1 -- On-Line -- Up 64 days 16:04:12 -- > 31456 Kbytes > > AIO I/O queues: > q name/id len maxlen totalops dskread dskwrite dskcopy > kio 0 0 0 0 0 0 0 > kio 1 0 33 1470835 1181578 289257 0 > kio 2 0 0 0 0 0 0 > [....] > > My Questions are: > 1) Why one server has 2 kio queues and the > other server has 3?. There will be one KAIO thread for each CPU VP configured. Check onstat -g ath. > 2) Is there any way to configure KAIO?. I looked at TFM and did > not find any clue Not in terms of the number of threads. You can choose to switch it off or on using environment variables or configuration parameters; check the release notes. > 3) Why only one kio queue is being used?. It is probably able to satisfy your IO needs. The max queue length gives you an idea of saturation. A length of 32 for kaio is nothing. Hope that helps, -- Mark. +----------------------------------------------------------+-----------+ |Mark D. Stock - Informix SA http://www.informix.com |//////// /| |mailto:mdstock@informix.com FAQ http://www.iiug.org |///// / //| | +-----------------------------------+//// / ///| | Tel: +27 11 807 0313 |If it's slow, the users complain. |/// / ////| | Fax: +27 11 807 2594 |If it's fast, the users keep quiet.|// / /////| |Cell: +27 83 250 2325 |Therefore, "No news: travels fast"!|/ ////////| +----------------------+-----------------------------------+-----------+