ubuntu - use a disk without paritioning it?

Solution 1:

As @Bib says in a comment above...

Creating a filesystem on a bare disk, without partitioning, is fully possible; you might even succeed overwriting a previous partition table/actions (clearing it? I have never tried that).

But then, I would not be surprised if there is at least one OS in the world that might not be 'happy' with it.

That would be:

$ sudo mkfs -t ext4 /dev/sdb