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Re: performance turning help

Posted in 1999

Topics: Performance & Tuning, Storage & Space Management, Jobs, Consulting & Announcements

Wayne Trieu — — source: Informix-list mailing list archive (1991-1998)

In article <7l2a73$tif$1@nnrp1.deja.com>, Yuri Dovgart <y_dovgart@tci.ukrtel.net> wrote: Hi Yuri, > > NUMAIOVPS 1 # Number of IO vps> > You are using kaio ? If not, increase NUMAIOVPS to at minimum the > number of your active disks. > How do I know if I am using KAIO? All my DB chunks are on RAW devices, is that means I should not use KAIO right? If this right how do I disabled KAIO? Thank you for your time. --Wayne > -- > With best regards, Yuri Dovgart, > SAP R/3, Informix consultant, > "Telecominvest" company. > E-mail y_dovgart@tci.ukrtel.net > > Sent via Deja.com http://www.deja.com/ > Share what you know. Learn what you don't. > -- Wayne Trieu Sent via Deja.com http://www.deja.com/ Share what you know. Learn what you don't.

↪ replying to Wayne Trieu
Roy Gvirtsman — — source: Informix-list mailing list archive (1991-1998)

Wayne, Check onstat -g ioq see maxlen. If it is large you are waiting for I/O. The question is why ? I/O requests are served by AIO/VPs and by CPU/VPs if KIO is enabled. By default it is. Run onstat -g ioq, if the display says KIO it is this. If it reads CPU then it is disabled. If it is enabled add another CPU/VP. If it is disabled add AIO/VP. Another reason can be highly fragmente tables. Run oncheck -pe dbsname:tabname for the largest tables.Check the number of extents. If it is over 30 then you disk is probably spending too much time in seeking. I hope this helps, Roy G. Wayne Trieu wrote: > In article <7l2a73$tif$1@nnrp1.deja.com>, > Yuri Dovgart <y_dovgart@tci.ukrtel.net> wrote: > > Hi Yuri, > > > > NUMAIOVPS 1 # Number of IO vps> > > > You are using kaio ? If not, increase NUMAIOVPS to at minimum the > > number of your active disks. > > > How do I know if I am using KAIO? > All my DB chunks are on RAW devices, is that means I should not use KAIO > right? If this right how do I disabled KAIO? > > Thank you for your time. > > --Wayne > > > -- > > With best regards, Yuri Dovgart, > > SAP R/3, Informix consultant, > > "Telecominvest" company. > > E-mail y_dovgart@tci.ukrtel.net > > > > Sent via Deja.com http://www.deja.com/ > > Share what you know. Learn what you don't. > > > > -- > Wayne Trieu > > Sent via Deja.com http://www.deja.com/ > Share what you know. Learn what you don't.

↪ replying to Wayne Trieu
Carlson@WHSmith — — source: Informix-list mailing list archive (1991-1998)

Wayne Trieu wrote: > > In article <7l2a73$tif$1@nnrp1.deja.com>, > Yuri Dovgart <y_dovgart@tci.ukrtel.net> wrote: > > Hi Yuri, > > > > NUMAIOVPS 1 # Number of IO vps> > > > You are using kaio ? If not, increase NUMAIOVPS to at minimum the > > number of your active disks. > > > How do I know if I am using KAIO? onstat -g iov | grep kio -- should show some lines like this: kio 0 i 0.0 0 0 0 0 0 0.0 0 kio 1 i 10.9 61165 33 61132 0 187727 0.3 0 kio 2 i 11.3 63137 0 63137 0 192499 0.3 0 kio 3 i 0.0 0 0 0 0 0 0.0 0 . . . if you're using KAIO > All my DB chunks are on RAW devices, is that means I should not use KAIO > right? If this right how do I disabled KAIO? Actually, KAIO is disabled by default. It is also recommended for raw devices. In order to enable it, set the environment variable KAIOON to 1 (as user informix) and bounce the engine. When Informix reboots, you should see a message about KAIO in the online.log. Beware, there are some versions of Informix on HPUX that don't give a performance boost using KAIO. We left KAIO disabled on our systems until the most recent release of IDS (7.30.uc7). John Carlson Informix DBA WHSmith USA

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