kswapd

From: Mario Camuņas (mario_camunas_at_hotmail.com)
Date: 10/01/03

  • Next message: TBrowder: "Re: Re: gdm and networking"
    To: redhat-list@redhat.com
    Date: Wed, 01 Oct 2003 10:51:02 +0200
    
    

    Hello:

      Our scenario is the following:

             One web server runninng kernel 2.4.9-e-12(smp), it is used to host an
    Apache webserver with an integrated application server. The system has 2Gb
    of RAM and 2Gb of swap. The last day an strange thing happened. We tried to
    connect to our system using ssh and we canīt, after many attempts we could
    connect to the system and saw that we couldnīt connect because there was a
    lack of memory. Every proccess you tried to start failed and gave the
    following error message" fork failed: Canīt allocate memory (errno=12)".

    The output of the free -k command showed that the swap space(there was only
    5 Mb of free RAM) wasnīt being used and we donīt understand why. We have
    found a lot of similar cases of systems that couldnīt fork but were plenty
    of unused swap space so we thought we would find answers for this problem
    but we havenīt found any(although we have looked for one a lot).

        We think that perhaps our freepages settings are too low( 1.6-4.5-7.4
    Mb) and if we merge this low values with an excesive fragmented memory this
    could explain our memory squeeze problems. Some of us have proposed the
    theory that everytime a proccess is started it needs a little quantity of
    contiguous memory and that if the system canīt provide it to the process it
    dies before the fork is completed. Any idea about what can be happening
    here?

       We have seen that kernel 2.4.9.e-24 seems to fix this kind of problems,
    what do you think?

       Apart from kernel upgrading we want to change the values(freepages) that
    control the swapping but we have seen in redhat release-notes that these
    parameters shouldnīt been changed(although it seems more a microsoft
    disclaimer"You are a fool so please donīt do anything with your system" than
    a real warning because there arenīt reasons about how can it spoil your
    system).

    http://www.redhat.com/docs/manuals/enterprise/RHEL-AS-2.1-Manual/release-notes/RELEASE-NOTES-U1

    Regards,
    Mario.
    Regards,
    Mario.

    _________________________________________________________________
    Descubre el mayor catálogo de coches de la Red en MSN Motor.
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  • Next message: TBrowder: "Re: Re: gdm and networking"

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