I have been trying to format my 640GB external Hard Drive in command-line and can't seem to get it working. I have done the following in order:sudo fdisk /dev/sda(Deleted any partitions, created a new partition, toggled partition type (tried multiple, but not sure the best?), then wrote the partition and printed to make sure it was correct.I then created the ext4 filesystem using: sudo mkfs.ext4 /dev/sda1I tried to mount the partition using: sudo mount -t ext4 /dev/sda1 /mnt/640-hdd -o gid=XXXX,uid=XXXXI then was given a mount error: mount: wrong fs type, bad option, bad superblock on /dev/sda1,    missing codepage or helper program, or other error    In some cases useful info is found in syslog - try    dmesg | tail  or soAny recommendations?FSTAB info:/dev/sda1       /mnt/640-hdd    ext4    defaults,uid=bwhite94,gid=bwhite94      0       0
Debian..Can't format and mount external HDD
debian;ext4;raspbian;fdisk;mkfs