The "uniqueness" of UUIDs

[Roger Price <debian@rogerprice.org>]

On Tue, 26 Nov 2024, George at Clug wrote:

> "$ lsblk -f" output is very nice !   Thanks.

I tried this and noticed UUID duplication in the output.  Here is part of what I 
saw:

NAME    FSTYPE            FSVER LABEL          UUID                                 FSAVAIL FSUSE% MOUNTPOINT
...
sdg
... 
├─sdg6  linux_raid_member 1.0   10.218.0.100:3 f5e37a29-357a-e3f2-c731-e29eddce5e91 
│ └─md3 ext4              1.0                  39c24711-ab43-497c-bf3e-12b4032575ac  758.4G     7% /mnt/home
...
sdh
... 
├─sdh6  linux_raid_member 1.0   10.218.0.100:3 f5e37a29-357a-e3f2-c731-e29eddce5e91 
│ └─md3 ext4              1.0                  39c24711-ab43-497c-bf3e-12b4032575ac  758.4G     7% /mnt/home

UUID sdg6 = UUID sdh6 !  If I wanted to retire /dev/sdg6 from the Raid array, I 
would not be able to use the UUID, only the unique SDxn.

Aren't UUIDs supposed to be unique?  Roger