Hi Peter,
Am 16.12.2025 um 23:03 schrieb [email protected]:
Hi,
How can existence of a given UUID within a system be tested in bash?
Preferably not restricting to a specific kind of device. Eg. avoiding
reference to /dev/disk.
My understanding is that UUIDs in general do not imply any particular
type of entity to be defined. In other words, youre free to label
anything with an UUID.
As you refer to /dev/disk I assume you think of UUIDs used to identify
storage in any way.
Now, for storage, we have an astonishing complex stack of layers:
particular attributes, files, file systems, block devices which can be
stored in partitions (or without) of other block devices, possibly LVs
that are members of VGs which span PVs where those can be on RAIDs which
can span partitions again which could be on other dive aggregates of all
sorts. In short, it's a mess or abitrary layers of things.
Most of those things can be identified by UUIDs.
Just as a first glimpse:
$ lsblk --help | grep UU
UUID filesystem UUID
PTUUID partition table identifier (usually UUID)
PARTTYPE partition type code or UUID
PARTUUID partition UUID
and below that I have
# mdadm --misc -D /dev/md12? | grep UUID
UUID : 6b39e3fd:41b943b3:670b85ed:c5d54346
UUID : 29eca8f7:aaa015b1:15052cc0:bf23ecab
UUID : e105b973:9d80d0b5:379ce26e:15dcc50b
and further down the stack:
# dmidecode | grep -i UUID
UUID: 00000000-0000-0000-0000-ac1f6b0e43f4
So, my question is -- which sort of thing identified by UUIDs are you
interested in?
Also, I believe that a better question would actually be "what problem
are you trying to solve?"
Cheers,
Arno
Thx, ... P.
--
Arno Lehmann
IT-Service Lehmann
Sandstr. 6, 49080 Osnabrück
