Re: Very low disk performance on 5.x

From: kama (kama_at_pvp.se)
Date: 05/02/05

  • Next message: Poul-Henning Kamp: "Re: Very low disk performance on 5.x" 
    Date: Mon, 2 May 2005 14:48:33 +0200 (CEST)
To: Eric Anderson <anderson@centtech.com>

    On Mon, 2 May 2005, Eric Anderson wrote:

    > I'll be honest here, I don't care much if the speed difference between
    > 4.X and 5.X is measureable, or whatever. What I find is a little
    > telling of an issue somewhere, is that READS are slower than WRITES!
    > This is totally bogus to me - dd'ing a file to a filesystem, then
    > umounting should take longer than dd'ing from the disk to /dev/null, it
    > nearly every config I can dream up. Maybe it's the speed at which
    > /dev/null can gobble bits (seems highly unlikely!), or maybe GEOM is
    > busy doing a check or some routine to data being accessed directly from
    > the disk device instead of through a filesystem? I don't know, but it
    > is an issue, and I'm sure we'll get nailed up to a fence in some
    > benchmark somewhere if we don't fix it..

    dev-null is not the issue... my own written testprogram that only read up
    data to a buffer in memory showed the same results as doing a dd to
    dev-null.

    /Bjorn
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  • Next message: Poul-Henning Kamp: "Re: Very low disk performance on 5.x"

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