1. Get the Information
Sometimes, devices don't automount, in which case you should try to manually mount them. First, you must know what device you are dealing with and what filesystem it is formatted with. Most flash drives are FAT16 or FAT32 and most external hard disks are NTFS. Type the following:
sudo fdisk -lFind your device in the list. It is probably something like /dev/sdb1. For more information about filesystems, see LinuxFilesystemsExplained.
2. Create the Mount Point
Now we need to create a mount point for the device. Let's say we want to call it "external". You can call it whatever you want, but if you use spaces in the name it gets a little more complicated. Instead, use an underscore to separate words (like "my_external"). Create the mount point:
sudo mkdir /media/external
3. Mount the Drive
We can now mount the drive. Let's say the device is /dev/sdb1, the filesystem is FAT16 or FAT32 (like it is for most USB flash drives), and we want to mount it at /media/external (having already created the mount point):
sudo mount -t vfat /dev/sdb1 /media/external -o uid=1000,gid=1000,utf8,dmask=027,fmask=137The options following the "-o" give you ownership of the drive, and the masks allow for extra security for file system permissions. If you don't use those extra options you may not be able to read and write the drive with your regular username.
Otherwise, if the device is formatted with NTFS, run:
sudo mount -t ntfs-3g /dev/sdb1 /media/external
Note: You must have the ntfs-3g driver installed. See MountingWindowsPartitions for more information.
4. Unmounting the Drive
When you are finished with the device, don't forget to unmount the drive before disconnecting it. Assuming /dev/sdb1 is mounted at /media/external, you can either unmount using the device or the mount point:
sudo umount /dev/sdb1or:
sudo umount /media/externalYou cannot unmount from the desktop by right-clicking the icon if the drive was manually mounted.
This information is taken from https://help.ubuntu.com/community/Mount/USB