Manually mount USB hard disk

Ref: https://help.ubuntu.com/community/Mount/USB

# Find details of the hard disk
fdisk -l

# Create directory in /media
sudo mkdir /media/external

# Mount drive
# FAT16 or FAT32
sudo mount -t vfat /dev/sdb1 /media/external -o uid=1000,gid=100,utf8,dmask=027,fmask=137

# NTFS
sudo mount -t ntfs-3g /dev/sdb1 /media/external

# Unmount before plugging out
sudo umount /media/external