HP-UX Kernel AIO
Posted in 1998
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