plug in and out USB card reader several times, ran out of /dev/sd* - Portable

This is a discussion on plug in and out USB card reader several times, ran out of /dev/sd* - Portable ; I notice when I plug a USB four in one flash card reader in and out several times, successively higher /dev files are assigned. sda sdb sdc sdd, sde sdf sdg sdh,... before long (sdh), I have exceeded the /dev/sd* ...

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Thread: plug in and out USB card reader several times, ran out of /dev/sd*

  1. plug in and out USB card reader several times, ran out of /dev/sd*

    I notice when I plug a USB four in one flash card reader in and out
    several times, successively higher /dev files are assigned.
    sda sdb sdc sdd,
    sde sdf sdg sdh,...
    before long (sdh), I have exceeded the /dev/sd* files on the machine.
    That means I must reboot if I want to mount the device?

  2. Re: plug in and out USB card reader several times, ran out of /dev/sd*

    On Sat, 23 Jul 2005 06:07:40 +0800, Dan Jacobson staggered into the
    Black Sun and said:
    > I notice when I plug a USB four in one flash card reader in and out
    > several times, successively higher /dev files are assigned. sda sdb
    > sdc sdd...


    Hm. Which version of which distro are you using? (Always include that
    information!) This sounds like a bug that should've been fixed a long
    time ago, so post the output of "uname -a".

    > before long (sdh), I have exceeded the /dev/sd* files on the machine.
    > [Does this mean] I must reboot if I want to mount the device?


    Nope. /usr/src/linux/Documentation/devices.txt lists the major and
    minor numbers for SCSI disks up to /dev/sdiv (256th SCSI disk). Use
    mknod with the right numbers and you can create more device nodes for
    more SCSI disks if you need them. Like "mknod /dev/sdq b 65 0" creates
    /dev/sdq , 17th SCSI disk whole disk. Or use the MAKEDEV script which
    may be in /dev if you're using a distro that hasn't moved to udev yet.

    The best long-term bet is to figure out why this is happening and fix
    it. A kernel upgrade may be the best way to do that.

    --
    Matt G|There is no Darkness in Eternity/But only Light too dim for us to see
    Brainbench MVP for Linux Admin / mail: TRAP + SPAN don't belong
    http://www.brainbench.com /
    -----------------------------/ This space sort of for rent.

  3. Re: plug in and out USB card reader several times, ran out of /dev/sd*

    Hi,

    On 2005-07-22, Dan Jacobson wrote:
    > I notice when I plug a USB four in one flash card reader in and out
    > several times, successively higher /dev files are assigned.
    > sda sdb sdc sdd,
    > sde sdf sdg sdh,...
    > before long (sdh), I have exceeded the /dev/sd* files on the machine.
    > That means I must reboot if I want to mount the device?
    >

    This really sounds like something is still mounted and you are effectively
    ripping out the rug from under Linux's feet.

    Before you unplug the USB device you should 'rmmod ' for whatver
    module it uses (look in 'lsmod' for a good guess).

    Then unplug the device and see what happens. If it starts to behave, I think
    you will find it will, then you can work out a more automagic approach.

    Cheers

    Alex

  4. Re: plug in and out USB card reader several times, ran out of /dev/sd*

    "Dan Jacobson" wrote in message
    news:87zmse8pg3.fsf@jidanni.org...
    >I notice when I plug a USB four in one flash card reader in and out
    > several times, successively higher /dev files are assigned.
    > sda sdb sdc sdd,
    > sde sdf sdg sdh,...
    > before long (sdh), I have exceeded the /dev/sd* files on the machine.
    > That means I must reboot if I want to mount the device?


    Sounds like you are unplugging the USB device before you have unmounted it!
    IFAIK this leaves the SCSI subsystem thinking your device has died, so it
    does not know what to do with it.

    If you type 'dmesg' in a terminal you will see messages from the SCSI/USB
    modules



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