Support for disks without a partition

[brassy-endomorph]

Likely the use of a is_virtual partition flag would work and allow us to keep the table hierarchy we need.

Trying to mash both disks and partitions in to a single table hasn't worked out well because the NOT NULL and other checks start to fall apart and we have to do a lot of work in the DB to approximate the constraints we get with just two tables. I am a fan of aggressive constraints within the DB to prevent unexpected (i.e., corrupt data) from ever getting in there to begin with.