Re: HP-UX Kernel AIO

Hi Sean, The information enclosed in the Informix standard release notes are accurate as far as I could see. All these were only good if we assumed KAIO function on the Operating System is healthy. From our experience on supporting various UNIX platform with Informix, We have learned KAIO is a 'NO-GO' area for HP-UX, it works fine for AIX (For sure) and SUN Solaris. We are using KAIO on AIX but have to withdraw the use for HP-UX sometime ago. We have not bothered to try to get back to it on HP-UX mainly the really benefits once can expect from KAIO is only about 10% improvement. Things may have changed since the last time we used it, but my experience on another DBMS product which also recommended against the use of KAIO on HP-UX sepcifically. Anyway to answer your question if you have to reboot your system on configuring KAIO on HP-UX. Yes, you will have to, because it must be enabled in the kernel thru kernel configuration. Also, the patches you have to install would could reboot to the system. regards Tim Lim In article <3667c6e4.0@145.227.194.253>, "Sean Kelsey" <seank@teepee.demon.co.uk> wrote: > Informix 7.24.UC5 on HP-UX 11 > > We hope to implement Kernel AIO on our HP/800 box running HP-UX 11 but have > a few questions. The ONLINE_7.2 documentation says that KAIO is available > but mentions patches that appear to be for version 10.01 & 10.10. The > ONLINE_7.2 document says:- > > =============================== > Kernel Asynchronous I/O (KAIO) is supported on this platform. However, it > is DISABLED by default. To enable KAIO set the environment variable > KAIOON. It is only effective on raw partitions. > > KAIOON=1; export KAIOON (for Bourne or Korn Shell) > > setenv KAIOON 1 (for C Shell) > > The following is a pre-requisite for using KAIO: > > o. HP KAIO driver "asyncdsk" is installed and linked into the > kernel. > > o. To ensure KAIO driver is up and running, check to see if there > is /dev/async, if not follow these steps: > > 1) su root > 2) /usr/sbin/mknod /dev/async c 101 1 > 3) chmod 0666 /dev/async > > To improve the performance of the server, the KAIO interface is > modified in this version of OnLine. It is suggested to have the > following patches installed on the system. > > 10.01/700 PHKL_6660 Select System Call performance patch > 10.01/800 PHKL_6661 Select System Call performance patch > 10.10/700 PHKL_6662 Select System Call performance patch > 10.10/800 PHKL_6663 Select System Call performance patch > > An environment variable IFMX_HPKAIO_NUM_REQ is provided to specify > the number of simultaneous KAIO requests that are processed by the > server at one time. The value can be set in the range of 10 to 5000, > the default being 1000. If the error > > "KAIO: out of OS resources, errno = %d, pid = %d" occurs, > consider increasing the value of IFMX_HPKAIO_NUM_REQ. > > IFMX_HPKAIO_NUM_REQ=2300; export IFMX_HPKAIO_NUM_REQ > (for Bourne or Korn Shell) > > setenv IFMX_HPKAIO_NUM_REQ 2300 (for C Shell) > ===================== > > My questions are:- > > 1. Will the above async procedures configure the HP KAIO driver correctly ?? > 2. Do these patches still need to be applied ( even though they look like > patches for 10.01 and 10.10 ) and if not, are there 11.x equivalents ?? > 3. What recommended settings should I use for the IFMX_HPKAIO_NUM_REQ > parameter so that I don't run out of KAIO OS resource ( we have 36 raw > partitions )?? > 4. Will I need to bounce the server as well as the engine ?? > 5. When ( and where ) do I need to set the KAIOON parameter ?? > > All answers very much appreciated > > TIA > > Sean > > -----------== Posted via Deja News, The Discussion Network ==---------- http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own