Re: Why I don't like UUIDs (Re: can't mount sdf1 in stretch, gparted claims its fat32)
On Tue, Feb 04, 2020 at 07:04:16PM -0500, Stefan Monnier wrote:
Me too, so I usually label the permanent stuff at least. UUID's can and
will change for no detectable reason.
For those reading along or finding this in search results: no, filesystem
UUIDs don't change for no detectable reason. Don't implement anything based
on this theory.
What he meant is that filesystem UUIDs are (re)created automatically
based on a heuristic of what it means for a filesystem to be "the same".
You understand that he didn't actually say that, right? This seems like
your own personal bugaboo instead.
While I'm sure this can be managed by explicitly setting UUIDs, I've
found it much more pleasant to manage explicit names (I personally
prefer LVM names over filesystem labels, but filesystem labels work well
for those filesystems I don't put under LVM). Not only I can pronounce
them and they carry meaning, but they tend to be much more visible (and
hence easier to manipulate).
I dislike using names becaues it's *much* more common to find name
collisions than UUID collisions. (E.g., a bunch of disks with
filesystems all labeled with easy to remember names like "root" or
"home".) Reboot with a couple of those in your system on a
label-oriented configuration and you may have a very bad day. LVM is
more resistant to that as long as you keep the vg names unique. (Call
everything vg0 and you're back to having a bad day.)
On Tue, Feb 04, 2020 at 10:19:25PM -0500, Stefan Monnier wrote:
PS: The only problem with LVM names is that Linux doesn't let you
rename a volume group while it's active (at least last time I tried),
which makes it painful to rename the volume group in which lives your
root partition.
How painful is it to dd a live cd, boot from it and rename?
Very. It's called "downtime".
Every time you have to reboot, it means your OS has somewhat failed you.
I'm trying to think of a reason to rename the root partition that
doesn't involve downtime and coming up empty.
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