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Thread: USB device not available

  1. #1
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    Default USB device not available

    Suse 11.4 32bit. Formerly when I plugged in the first USB device it would be identified as /dev/sdb, my primary SATA drive being /dev/sda. The second USB device as /dev/sdc and so on. That has now changed so that the first USB device is /dev/sdc, second one /dev/sdd etc. This causes havoc with several backup scripts. How can I revert to previous assignments?

    Thanks.

  2. #2
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    Default Re: USB device not available

    What does

    fdisk -l

    show?
    Tumbleweed_KDE
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  3. #3
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    Default Re: USB device not available

    Quote Originally Posted by caf4926 View Post
    What does

    fdisk -l

    show?
    # fdisk -l

    Disk /dev/sda: 16.1 GB, 16139354112 bytes
    255 heads, 63 sectors/track, 1962 cylinders, total 31522176 sectors
    Units = sectors of 1 * 512 = 512 bytes
    Sector size (logical/physical): 512 bytes / 512 bytes
    I/O size (minimum/optimal): 512 bytes / 512 bytes
    Disk identifier: 0x0008e91d

    Device Boot Start End Blocks Id System
    /dev/sda1 2048 3051519 1524736 82 Linux swap / Solaris
    /dev/sda2 * 3051520 31522175 14235328 83 Linux

    Disk /dev/sdc: 8054 MB, 8054636032 bytes
    248 heads, 62 sectors/track, 1023 cylinders, total 15731711 sectors
    Units = sectors of 1 * 512 = 512 bytes
    Sector size (logical/physical): 512 bytes / 512 bytes
    I/O size (minimum/optimal): 512 bytes / 512 bytes
    Disk identifier: 0x3aeea1b9

    Device Boot Start End Blocks Id System
    /dev/sdc1 62 15729647 7864793 83 Linux

  4. #4
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    Default Re: USB device not available

    In any case it is much better to give the file systems on those devices a label. They will be mounted by their label on /media/<label>. Or you can make entries in your fstab for mounting them by label (using /dev/disk/by-label/... instead of /dev/sd.), thus the correct file systems will be mounted on the correct mount-points.

    Using sda,sdb, etc allways depends on the sequence the system detected the devices and thus even a simple mistake by the operator in inserting the USB devices can create havoc.

    (Oh, and next time you post computers output, can you please put it between CODE tags: Posting in Code Tags - A Guide? Especialy fdisk -l listings become unreadable without them).
    Henk van Velden

  5. #5
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    Default Re: USB device not available

    Quote Originally Posted by hcvv View Post
    (Oh, and next time you post computers output, can you please put it between CODE tags: Posting in Code Tags - A Guide? Especialy fdisk -l listings become unreadable without them).
    I am having a little trouble getting these instructions to work. Is it possible that I need to have Java script enabled to do so?

  6. #6
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    Default Re: USB device not available

    I guess not. The most simple way is typing the words CODE between [ and ] before the output and /CODE, also between [ and ] after it. ( have to explain it like that, because doing it would produce
    Code:
    this is between them
    But I usualy click the Advanced button below the the Quick reaction field I am typing this in and then use the button with the # to create those tags. It could be that this more "sophisticated" way needs Java.
    Henk van Velden

  7. #7
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    Default Re: USB device not available

    Returning to the original problem (sdc1 instead of sdb1), after several reboots it reverted to the original sdb1. I don't know why it happened, other than I was experimenting with a new backup script on a new netbook, and at least twice the system froze and needed a hard reset. I suspect something related to the /sys directory. I am considering using the "/dev/disk/by-label" method although it does complicate things as I am using different USB drives.

    Thank you for your patient assistance.

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