[lkml]   [1999]   [Jun]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRE: UUIDs (and devfs and major/minor numbers)
    Looking at this from a _sysadmin_ point of view, not a technical one, here's
    a few thoughts.
    Oh, btw, please _don't_ CC: to me. The list will do nicely.

    UUID=3e6be9de-8139-11d1-9106-a43f08d823a6 /boot ext2 noauto 0 0

    Regarding the above: not a good idea as it stands.
    It's probably easier to mistype a lengthy [humanly-] unintelligible number
    than cross two cables.

    I would prefer to see:

    /dev/somedisk /boot ext2
    noauto,uuid=3e6be9de-8139-11d1-9106-a43f08d823a6 0 0


    /dev/somedisk /boot ext2 noauto,label=boot 0 0

    and use the uuid/label as a check, not a mechanism for mounting.
    Remember that /etc/fstab also documents to the _human_ sysadmin which disk
    is used where.
    That is, "/dev/scsi/c0t0d0..." relates to a physical position within a disk
    rack; a uuid does not.

    As far as devfs is concerned, I think it addresses many issues. For those
    "this is a user-space issue"
    people who advocate /proc/dev/.... and read the information out with
    scripts/a daemon, consider:
    If you're going to publish the information anyway, why not put it in the
    right place first time?
    I agree that _adapter_ information should go in /proc - they have io/irq
    data etc, but _disks_ go in /dev.

    Devfs offers a very good, logical interface. It's tidy (no wasted entries,
    no node creation. Believe me,
    /dev on *big* unix systems [AlphaServers, 100+ disks, FibreChannel,
    individually addressed by LUN]
    is exceptionally messy.). It's even human-readable to boot. On how you deal
    with persistance of
    ownership/mode over reboot, I have no comment. That's probably a site-issue.
    Symlinks, too, to
    name devices according to _your_ preference, are a site-issue.

    However, for NFS purposes, I prefer the idea of numbers, not names. The
    client does not need to know
    the actual physical location (in a disk rack) of the disk - that's a server
    issue. It just needs a reference,
    a "device descriptor" if you like. A major/minor system here is clearly
    easier, but a _human_ need not
    have to deal with these on a filesystem.

    Ian Woodhouse (
    Hyder IT Unix Systems (x45109)
    07775 533594 (mobile)
    01656 765109 (direct)

    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to
    Please read the FAQ at

     \ /
      Last update: 2005-03-22 13:52    [W:0.021 / U:4.552 seconds]
    ©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site