On Wed, Feb 05, 2020 at 07:33:38PM -0600, David Wright wrote:
On Wed 05 Feb 2020 at 15:59:27 (-0500), Michael Stone wrote:
On Wed, Feb 05, 2020 at 01:43:37PM -0600, David Wright wrote:
> On Wed 05 Feb 2020 at 09:00:41 (-0500), Michael Stone wrote:
> > On Tue, Feb 04, 2020 at 07:04:16PM -0500, Stefan Monnier wrote:
> > > 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.
>
> Rather a strawman argument there. There's no reason not to choose
> sensible LABELs, unlike the examples you've given there, which fail
> for at least two reasons: they're unlikely to be unique and they're
> too overloaded with meaning.
What does "sensible" mean in this context? On a static system all of
this is a complete waste of time because nothing changes. If you start
upgrading disks, using external drives, moving things around, etc., it
may very well be that the same "sensible" label applies to a
filesystem found on more than one disk.
To make that argument, you have to put scare quotes round sensible
because common sense would lead you to use different LABELs for
partitions that you intend to distinguish by LABEL. To do otherwise
would be like suggesting that two teams who play in red should do
so without a change of shirt for one team.
You seem to just be stuck in this mindset where you think that it's
somehow weird or unusual to name a root filesystem "root" instead of
"kumquat" or some other meaningless string. I don't really have a
response to that except to note that in my experience your naming
conventions are an outlier and that it's a waste of time making
assertions about what people should use as names instead of simply
acknowledging what people actually use as names.
Can problems be avoided
through careful attention to detail?
I'd call the LABEL problem's solution blindingly obvious. Ironically,
one has to be more careful with *certain* operations when using UUIDs
because one is less likely to spot a duplication. I'm thinking of,
say, copying partitions.
Again, asserting that using labels in a fashion that avoids potential
collisions is "blindlingly obvious" implies that the problems I've seen
people have with label-based schemes must mean that they're too ignorant
to do the "obviously" correct thing. That seems presumptuous at least.
OTOH, following best practices when copying raw partitions (including
changing the UUID) seems to be something to be glossed over (presumably
because only changing the label in that exact case is "obvious"?)
Stefan and I were posting why we like names. The uniqueness of UUIDs
is a given. (Ironically, it's in the name.)
Perhaps (although the fact that they won't be unique if you copy the raw
filesystem is a recurring theme) but the argument at the top of the
thread seems to be that they somehow change unexpectedly and can't be
relied upon--which would seem to be an even more serious problem (if it
existed).
And it's a different
argument from the one you appeared to make,
Yes, I argued against the proposition that actually started the thread,
which seemed to be that UUIDs are somehow unreliable--in particular,
as compared to labels. For some reason talking about why that isn't
actually the case makes you start talking about straw men, as though you
either didn't read or couldn't remember posts from a couple of days ago.
which was that you dislike
using names because other people (presumably) misuse them.
And you've explained that anybody who uses them other than in the
(extremely idiosyncratic) manner you prescribe is just doing them wrong
and its their own fault if there are problems because they must be dumb.
I'm glad we've managed to so succinctly summarize each other's position.
If I were to summarize my own position it would simply be that I
encourage people to be aware of potential issues that arise when labels
collide, and that UUIDs are a (not unreliable) alternative that may work
better in some circumstances.
OK, perhaps
you run a helpdesk.
The closest I come to that is this mailing list.
Just because you personally use a
feature in a particular way doesn't mean everyone else does. Sometimes
a standard install of an OS can default to labeling schemes that cause
conflicts if you put the drive from one machine into another
machine--so this really isn't something I'm making up out of thin air
that never happens in real life.
IIRC you're describing Debian in the early days, when partitions were
configured only by their kernel names, rather like some people prefer
their network interfaces to be named.
Nope...you need experience with more systems. :)
> > 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.)
>
> It seems that saying "keep the vg names unique" is not very different
> from saying to keep filesystem LABELs unique.
It's pretty much exactly the same. If you have multiple logical
entities addressed by the same name, you might not get the entity you
expected to get. This isn't always obvious to someone starting out who
reads something like "labels prevent problems" and hasn't yet run into
cases where that isn't true and thus hasn't adopted strategies to
avoid those problems.
That's another strawman argument: I haven't suggested that
What is "that"? You said "It seems that saying 'keep the vg names
unique' is not very different from saying to keep filesystem LABELs
unique." I agreed, then clarified what the issue is if they aren't
unique. Then I explained why I think this is an important point to
emphasize. I'm confused about what it is that you think that I think you
suggested.
, you bring
it up, then knock it down: isn't that the definition of a strawman
argument?
No. You seem to just like to say "strawman argument" regardless of
whether it's applicable. Keep tilting at those straw windmills, I guess?
