Re: spreading partitions over multiple drives

From: Willem Jan Withagen (wjw_at_withagen.nl)
Date: 09/10/04

  • Next message: Geert Hendrickx: "Re: spreading partitions over multiple drives"
    Date: Fri, 10 Sep 2004 15:21:46 +0200
    To: Geert Hendrickx <geert.hendrickx@ua.ac.be>
    
    

    Geert Hendrickx wrote:

    >>Not for this usage.
    >>
    >>
    >>>Fragmentation may be LESS of a problem with UFS, but a moving target
    >>>like one big /usr (incl src, obj, ports) will get fragmented as well.
    >>>
    >>>
    >>This is how you see it. I have not heard that there is any tool to help
    >>here.
    >>
    >>I would not call this fragmentation. It is more like spreading the files
    >>from one directory all over the disk.
    >>
    >>
    >
    >Ok but the effect is the same: constant movement of the head.
    >
    >
    I would expect a bigger system to cache just about all file access
    during 'make buildworld'.
    Even when building things with -j 64 I can not get my dual-opteron 1Gb
    system get without free pages.
    And as such most files will only be read once, and object output will be
    "slowly" synced on the disks.
    Disk I/O rearly becomes the bottleneck, most of the time I'm missing raw
    CPU cycles.
    And I have everything on 1 large 200Gb disk.

    >>>Splitting up partitions would reduce this fragmentation (as you are
    >>>essentially defining some "super large blocks"), and may increase
    >>>filesystem stability in case of crashes etc.
    >>>
    >>>
    >>>
    >>It might not affect stability but it increases the chances to fix a
    >>problem in case of a crash.
    >>
    >>
    >
    >Yes I meant stability of the filesystem not of the running OS.
    >
    >
    >Ok but the original question was about spreading partitions amongst
    >multiple disks, not pro/con splitting partitions on one disk. :-)
    >
    >
    My major problem with a lot of partitions has always been that one way
    or antoher I outgrow a partition and then all of a sudden the logic
    needs to be skewed for space reasons. Finaly disks start to grow to the
    size where this becomes a moot point. 10Gb for /usr will last me until
    we get to the next step of disk-sizes.

    Having things on different spindles will of course be a major plus.

    --WjW

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  • Next message: Geert Hendrickx: "Re: spreading partitions over multiple drives"

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