[Linux] How to partition, format, and mount a second harddrive

Let's assume the second harddrive is /dev/sdb

first, partition it

$ sudo fdisk /dev/sdb
it has self-explanining CLI

If you create just one primary partition, it will give /dev/sdb1.
We are going to format and mount sdb1

formatting
$ mkfs.ext4 /dev/sdb1

mounting

add a line in /etc/fstab

# second harddrive (sdb1)
/dev/sdb1 /mnt ext4 defaults 0 0

then do this
$ sudo mount -a