by summers » Tue Feb 09, 2016 10:40 am
PARTUUID is shorter with MBR, as MBR doesn't do UUID intrinscially - so linux fudges a UUID for the UUID for the disk/partition table.
However with GPT, the UUID is part of specication of the (G in GPT stands for GUID, which means globally unique identifier - e.g. the UUID).
So GPT UUIDs are high quality UUID, and long. MBR UUID are a hack and short.
So does make me wonder what happens with a hybrid partition table, e.g. both MBR and GPT. One would seem to be able to use either UUID. But what you've found is that it isn't possible to use the GPT UUID in a hybrid partition table.