turning on KAIO

Posted in 2000

Summary

Steven couldn't start IDS 7.30UC7XB on HP-UX 11 after setting KAIOON=1 and IFMX_HPKAIO_NUM_REQ, and couldn't find the HP "asyncdsk" KAIO driver. He solved it himself: asyncdsk isn't enabled by default, so he used SAM to add the asyncdsk driver, rebuilt the kernel and rebooted, after which the release-notes steps worked (kio in onstat -g ioq and kaio threads in onstat -g ath indicating KAIO use). His follow-up questions about tuning KAIO thread counts went unanswered. On HP-UX 10.20 with 7.24, one poster reported ~25% gain with latest patches, while another warned a bug caused very slow I/O.

Auto-generated by DrWatson from the posts below — may be imperfect; read the full thread.

Topics: Installation, Setup & Upgrades, Platform-Specific Issues

Steven — Sat, 26 Feb 2000 21:25:20 +0800 — source: Informix-list mailing list archive (1991-1998)

Hi, Just managed to upgrade my IDS from 7.24UC4X1 to 7.30UC7XB on HP-UX 11. Was trying to turn on KAIO by doing the following added setenv KAIOON 1 setenv IFMX_HPKAIO_NUM_REQ 2300 but was unable to start up my IDS. From the documentation, I seems to need HP KAIO driver "asyncdsk" but was not able to find any patch resembling this anywhere on HP website. Anyone got any idea on how I may proceed? Btw, once, if, KAIO is started, I can reduce the number of aio vps to 2 or something like that? thanks for the help. Steven

↪ replying to Steven

Steven — Tue, 29 Feb 2000 11:22:23 +0800 — source: Informix-list mailing list archive (1991-1998)

in article B4DDF53F.191C%steven_lee@jjsea.com, Steven at steven_lee@jjsea.com wrote on 26/02/2000 09:25 PM: > Hi, > Just managed to upgrade my IDS from 7.24UC4X1 to 7.30UC7XB on HP-UX 11. > > Was trying to turn on KAIO by doing the following > > added > setenv KAIOON 1 > setenv IFMX_HPKAIO_NUM_REQ 2300 > > but was unable to start up my IDS. > > From the documentation, I seems to need HP KAIO driver "asyncdsk" but was > not able to find any patch resembling this anywhere on HP website. > Anyone got any idea on how I may proceed? > > Btw, once, if, KAIO is started, I can reduce the number of aio vps to 2 or > something like that? > > thanks for the help. > Steven > Thanks for all the great help. asyncdsk is not turned on by default, and the problem was solved once I used SAM (HPUX) to add in the asyncdsk driver to the kernel, rebuilt the kernel and then reboot the system. After that, I followed the instructions in the release notes, and Informix managed to start up. is it true that if I see kio under "onstat -g ioq" means that KAIO is turned on? I also see kaio under "onstat -g ath", which I guess KAIO is being used now. Is it possible to change the number of KAIO threads or are they dependent on the number of CPUVP & AIOVPs? The above was done on my HPUX 11.0. Had anyone tried KAIO with Informix 7.24 on HPUX 10.20? Thanks again for all the help. rgds Steven

↪ replying to Steven

Sergey Turin — Tue, 29 Feb 2000 10:38:24 +0300 — source: Informix-list mailing list archive (1991-1998)

> > The above was done on my HPUX 11.0. Had anyone tried KAIO with Informix 7.24 > on HPUX 10.20? > Yes, see details below. Sergey Environment HP-UX 10.20 with latest patch bundle installed (very important) Informix Dynamic Server 7.24UC4X3 KAIO is on for at least 2 years Performance increase appr.25% Server 2 CPU's (single CPU VP though) Data size 8G, OLTP apps Model K220

↪ replying to Steven

Neil Truby — Wed, 1 Mar 2000 00:03:19 -0000 — source: Informix-list mailing list archive (1991-1998)

Steven wrote in message ... > >The above was done on my HPUX 11.0. Had anyone tried KAIO with Informix 7.24 >on HPUX 10.20? Indeed. It's to be avoided like the plague, as a bug causes very slow i/os with it on. Neil

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Glossary

IDS (Informix Dynamic Server)