On Tue, 26 Nov 2024, to...@tuxteam.de wrote:
On Tue, Nov 26, 2024 at 03:53:28PM +0100, Roger Price wrote:
"except via mdadm" : exactly the point I would like to make. mdadm needs to
be able to address the individual underlying devices. Only /dev/sdxn style
addressing can do this, not duplicate UUIDs, or duplicate LABELs.
If those we are talking about are file system UUIDs/LABELs (and all evidence
supports that), they *are not* duplicate. They are *the same*. Change "one"
and *poof* the "other" will change along. Because they are on the file system,
which is sitting astride your MD devices.
My understanding is that a Linux file system is a hierachical structure starting
with the root directory (/) which organises the directories and files. The
files are stored on various devices which have identities such as /dev/sdxn,
UUID or LABEL. These identities are for the devices, not parts of the file
system.
The file system and the underlying devices are separate notions, which is why I
don't understand your phrase "file system UUIDs/LABELs".
The directory with name /home could be on device with identity /dev/sda2 (or
UUID xxxx), but although closely associated in /etc/mtab, neither /dev/sda2 nor
UUID xxxx is the identity of the directory.
Roger
