This is happen because when a device is mounted is mounted under your name and so, the system think that is yours and only you should have access to it. To pass by this you can simply unplug and plug again that device when you switch to another account, or...
From this output:
total 0
lrwxrwxrwx 1 root root 10 Oct 2 18:34 3C18F90318F8BD48 -> ../../sdb3
lrwxrwxrwx 1 root root 10 Oct 2 18:34 5e89f82b-dea9-4348-88f9-ac5cd533437f -> ../../sdb9
lrwxrwxrwx 1 root root 10 Oct 2 18:34 648660B6866089FE -> ../../sda2
lrwxrwxrwx 1 root root 10 Oct 2 18:34 8012db19-0086-4576-96a2-34f50a75ecfb -> ../../sdb8
lrwxrwxrwx 1 root root 10 Oct 2 18:34 88EAB7AEEAB796C2 -> ../../sdb6
lrwxrwxrwx 1 root root 10 Oct 2 21:23 8AD65635D65621AD -> ../../sdb2
lrwxrwxrwx 1 root root 10 Oct 2 18:34 96C01076C0105EB5 -> ../../sda3
I can understand that you have probably more than one device plugged. Let's take for example sdb2
- it was the last one plugged. It's UUID is 8AD65635D65621AD
- keep this in mind.
First, make a group called let say my_device
(you can call it whatever else) and add your accounts to it. You will do these from terminal:
sudo groupadd my_device
sudo usermod -a -G my_device your_username
sudo usermod -a -G my_device another_username
#...
sudo usermod -a -G my_device last_username
Second, make a new folder called my_device
in /media
and give everyone in the my_device
group permission to read and write it:
sudo mkdir /media/my_device
sudo chown :my_device /media/my_device
sudo chmod 660 /media/my_device
Finally, open fstab
as root. Something like:
sudo -i gedit /etc/fstab
and add this line at the end:
UUID=8AD65635D65621AD /media/my_device vfat users,noauto,relatime 0 0
Save the file and close it. That's it
The same method can be applied for other devices.
Source: http://ubuntuforums.org/showthread.php?t=1684055
ls -l /dev/disk/by-uuid/
when that drive is plugged? – Radu Rădeanu Oct 02 '13 at 16:45