This partitioning scheme is used in DragonFlyBSD. It is similar to
BSD disklabel, but has the following improvements:
* metadata has own dedicated place and isn't accessible through partitions;
* all offsets are 64-bit;
* supports 16 partitions by default (has reserved place for more);
* has reserved place for backup label (but not yet implemented);
* has UUIDs for partitions and partition types;
No objections from: geom
MFC after: 2 weeks
Relnotes: yes
found inside extended partitions and used to create logical partitions.
At this time write/modify support is not (yet) present.
The EBR and MBR schemes both check the parent scheme. The MBR will
back-off when nested under another MBR, whereas the EBR only nests
under a MBR.
