Horrible file creation/deletion performance on aix5.2 with jfs2 - Aix

This is a discussion on Horrible file creation/deletion performance on aix5.2 with jfs2 - Aix ; I'm experiencing some really horrible performance problems on an AIX 5.2 machine with a jfs2 file system. Try the following: # make a dummy file dd if=/dev/zero of=tmp bs=1024k count=1 # time creating 1000 hardlinks time perl -e 'for ($i ...

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  1. Horrible file creation/deletion performance on aix5.2 with jfs2


    I'm experiencing some really horrible performance problems on an AIX
    5.2 machine with a jfs2 file system.

    Try the following:

    # make a dummy file
    dd if=/dev/zero of=tmp bs=1024k count=1

    # time creating 1000 hardlinks
    time perl -e 'for ($i = 1; $i < 1000; $i++) { link("tmp", "tmp.$i"); }'

    # time removing 1000 hardlinks
    time rm tmp.*

    Both creating the hardlinks and removing them takes about 7 _seconds_
    on my AIX machine (on a local disk). Other compareable OSes (Solaris,
    Linux, HP-UX, ...) can easily do this 100 times faster.

    So - I'm wondering, what am i missing? Is there some option somewhere
    I forgot to enable?

    - Finn Arne




  2. Re: Horrible file creation/deletion performance on aix5.2 with jfs2

    On Feb 6, 1:33 pm, Finn Arne Gangstad wrote:
    > I'm experiencing some really horrible performance problems on an AIX
    > 5.2 machine with a jfs2 file system.
    >
    > Try the following:
    >
    > # make a dummy file
    > dd if=/dev/zero of=tmp bs=1024k count=1
    >
    > # time creating 1000 hardlinks
    > time perl -e 'for ($i = 1; $i < 1000; $i++) { link("tmp", "tmp.$i"); }'
    >
    > # time removing 1000 hardlinks
    > time rm tmp.*
    >
    > Both creating the hardlinks and removing them takes about 7 _seconds_
    > on my AIX machine (on a local disk). Other compareable OSes (Solaris,
    > Linux, HP-UX, ...) can easily do this 100 times faster.
    >
    > So - I'm wondering, what am i missing? Is there some option somewhere
    > I forgot to enable?
    >
    > - Finn Arne



    september:/tmp# time perl -e 'for ($i = 1; $i < 1000; $i++)
    { link("tmp", "tmp.$i"); }'

    real 0m5.06s
    user 0m0.02s
    sys 0m0.11s
    september:/tmp# time rm tmp.*

    real 0m5.12s
    user 0m0.05s
    sys 0m0.10s

    Seems like user+sys is small. Real time is large because of disk I/O
    waits.
    I think jfs commits the change to disk before returning.
    --S


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