Adding a new linux disk:

Find the device (use dmesg)

Delete any partitions on the new disk:

fdisk /dev/sde

And add a new linux partition.

The use mkfs - in this case to create a ext4 filesystem

mkfs.ext4 /dev/sde1

Then tune the filesystem a little:

tune2fs -m 0 /dev/sde1
tune2fs -L backup2 /dev/sde1

-m 0 removes the reserved blocks
-L xxxx labels the filesystem