TrueNAS Scale using partition on disk when creating zpools

Hi,

I’m just getting started with using Truenas scale, and I imported all of my old zpools manually, but then created a manual test zpool from scratch using the UI.

It seems like it created a partition on the disk (I think there was one already so it may have reused it), and used that as the zpool identifier:

  pool: testing_zpool
 state: ONLINE
config:

	NAME                                    STATE     READ WRITE CKSUM
	testing_zpool                        ONLINE       0     0     0
	  aba50a84-8049-41e6-b2a6-a54d7324d2b7  ONLINE       0     0     0

errors: No known data errors

Was wondering if this is expected? From what I had read online I had expected truenas to use the whole disks.