[CentOS] UDEV rule allow users to unmount USB stick
kerplop at sbcglobal.net
Tue Dec 23 14:39:25 UTC 2008
Lanny Marcus wrote:
> On Mon, Dec 22, 2008 at 8:46 PM, MHR <mhullrich at gmail.com> wrote:
>> On Mon, Dec 22, 2008 at 4:19 PM, Philip Manuel <phil at zomojo.com> wrote:
>>> I'm trying to understand why a normal user is not allowed to unmount
>>> their USB stick? I think it is most likely a udev rule. does anyone know ?
>> If I understand this correctly, it's a mount/umount rule - normal
>> users cannot run root commands. They are written to disallow normal
>> users from performing root tasks.
>> However, if you are using gnome, you can use the gnome-umount command
>> (which is the equivalent of right-clicking the icon and selecting
>> "Unmount"). I suspect there is a similar analogue in KDE.
> Good explanation Mark. I use GNOME and I have zero problems with this. Lanny
Mark's assumption was correct. In KDE, the right-click menu item is
"Safely remove". I find it interesting, though, that root can manually
mount a USB drive from the command line and any user can "safely remove"
it via KDE. For example, I have this line in my fstab for a backup hard
LABEL=OT3 /media/OT3 ext3
Normally, it's mounted and unmounted by the backup script but I
discovered that if root manually mounts it
[root at mavis ~]# mount /media/OT3
[root at mavis ~]# mount
/dev/sda1 on /media/OT3 type ext3 (rw,noexec,nosuid,nodev)
[root at mavis ~]#
And I try to unmount it as my normal user, I run into the behavior that
is spelled out in the man page:
[rj at mavis ~]$ umount /media/OT3
umount: only root can unmount LABEL=OT3 from /media/OT3
[rj at mavis ~]$
However, I CAN unmount it using KDE. --*USUALLY*--
Occasionally, the desktop icon will indicate "unmounted" but either
attempting to mount the drive or manually examining /etc/mtab reveals
that the drive is stll mounted.
If one is to believe the mount man page, there is/are 1 or 2 bug(s) here.
So, Mark, KDE has a true analogue only if GNOME is similarly broken.
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