推理文by阿誠

Automounting (Ubuntu Server)
By default, disk drives do not automount in Ubuntu Server Edition. If you are looking for a lightweight solution that does not depend on HAL/DBUS, you can install "usbmount".

預設不會自動mount

1.sudo fdisk -l
2.sudo mkdir /media/external
3.sudo mount -t vfat /dev/sdb1 /media/external -o uid=1000,gid=1000,utf8,dmask=027,fmask=137
or sudo mount -t ntfs-3g /dev/sdb1 /media/external

unmount
sudo umount /dev/sdb1
or
sudo umount /media/external

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