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Thread: KAIO error

  1. #1
    Join Date
    Oct 2005

    Unanswered: KAIO error

    At continuous work in current of 5 months of a program complex of processing of payments of bank we have revealed a following problem: IDS 10.0 crashed at data exchange through KAIO. It is necessary to notice, that week the same crash has been revealed, but together with messages on loss of data at an exchange through KAIO in online.log (as well as in a today's case) in a system file of registration Linux (messages) have appeared records:

    Mar 22 12:00:55 server kernel: open files rlimit 1024 reached for uid 1000 pid 2
    UID 1000 – Informix

    I set parameters in a file/etc/security/limits.conf - soft nofile 2048 and hard nofile 4096. I have solved, that it can solve a problem, but it has appeared, that it not so. Today all has repeated, but already without records in /var/log/messages. Chunks are located on raw partition of a disk which in turn are on storehouse of data HP EVA5000. I hope for your help in the decision of a problem.

    Hardware and software:


    Linux SLES 9 SP3 x86_64
    kernel 2.6.5-7.244-smp
    IBM Informix Dynamic Server Version 10.00.FC5


    HP ProLiant DL580 G3
    2x Intel Xeon /3.334GHz
    2Gb RAM
    Internal Storage:
    36Gb Disk space - RAID1
    External Storage:
    50Gb HP EVA5000

    Mesages in online.log:

    08:39:46 Maximum server connections 43
    08:44:50 Checkpoint Completed: duration was 3 seconds.
    08:44:50 Checkpoint loguniq 29728, logpos 0x195f018, timestamp: 0xe4fdb06

    08:44:50 Maximum server connections 43
    08:45:16 Logical Log 29728 Complete, timestamp: 0xe514b52.
    08:49:17 KAIO: error in kaio_WRITE, kaiocbp = 0x63584cd0, errno = 0
    08:49:17 fildes = 259 (gfd 7), buf = 0x0x635aa000, nbytes = 8192, offset = 13580288
    08:49:17 KAIO: error in kaio_WRITE, kaiocbp = 0x63628cd0, errno = 0
    08:49:17 fildes = 260 (gfd 7), buf = 0x0x636db000, nbytes = 8192, offset = 13416448

    many many rows

    08:49:29 KAIO: error in kaio_WRITE, kaiocbp = 0x63276a10, errno = 0
    08:49:29 fildes = 259 (gfd 7), buf = 0x0x636a7000, nbytes = 8192, offset = 418633728
    08:49:29 KAIO: out of OS resources, errno = 11, pid = 10313
    08:49:29 rsmirror.c, line 1847, thread 163432, proc id 10315, INFORMIX-OnLine M
    Critical media failure..
    08:49:29 Fatal error in ADM VP at mt.c:13055
    08:49:29 Unexpected virtual processor termination, pid = 10315, exit = 0x100

    08:49:29 PANIC: Attempting to bring system down

  2. #2
    Join Date
    Apr 2007
    Jundiai / SP - Brasil

    I get this in Machine Notes:

    In your log say "out of OS resources"... maybe this can help....

    3. Kernel Asynchronous I/O (KAIO)

    Asynchronous I/O is supported by the official Linux kernel since version
    2.6.x. IBM Informix Dynamic Server supports Kernel Asynchronous I/O (KAIO)
    on character devices (a.k.a. raw devices) and block devices. It is enabled
    by default, and can be disabled by setting the environment variable
    KAIOOFF=1 in the environment of the process that brings up the server.

    When using KAIO, it is recommended to run poll threads on separate VPs by
    specifying NET as VP class in the NETTYPE onconfig parameter, e.g.
    NETTYPE ipcshm,...,...,NET or
    NETTYPE soctcp,...,...,NET

    On Linux, there is a system wide limit of the maximum number of parallel
    KAIO requests. The file /proc/sys/fs/aio-max-nr is containing this value.
    It can be increased by the Linux system administrator, e.g. by

    # echo new_value > /proc/sys/fs/aio-max-nr

    The current number of allocated requests of all OS processes is visible
    in /proc/sys/fs/aio-nr.

    By default, IBM Informix Dynamic server is allocating half of the maximum
    number of requests, and assigns them equally to the number of configured
    CPU VPs. The number of requests allocated per CPU VP can be controlled by
    the environment variable KAIOON, by setting it to the required value before
    bringing up the server. The minimum value for KAIOON is 100.
    If Linux is about to run out of KAIO resources, e.g. when dynamically adding
    many CPU VPs, warnings will be printed to the online.log file. In this case,
    the Linux system administrator should add KAIO resources as described above



  3. #3
    Join Date
    Oct 2005
    Many thanks!

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