Re: CD writing in future Linux (stirring up a hornets' nest)

[Martin Mares <mj@ucw.cz>]

Hello!

> This claim is a bit surprising since only, but the most irrelevant
> stuff from the dust bin of history, doesn't define a world global
> unique id those days.

That's unfortunately not true -- many USB devices don't have a usable
serial number.

Also, if I have a single device of its kind, let's say a USB mouse,
I really want to call it "The Mouse" and I don't want to reconfigure
anything if I plug it to a different port or replace it with a slightly
different mouse. All mice are considered equivalent by the user
as there is no reason to distinguish between them.

The same applies to CD burners -- as long as I have only one (which is
still the most common situation), I shouldn't have to think about how
to call it. Let it be just /dev/cdrw.

When I get multiple such devices, things start getting interesting, but
there is no single naming strategy which fits all uses. For example,
if I have two USB ports into which I connect USB disks various people
bring to me, it's convenient to call them "left" and "right", because
the serial number doesn't mean anything to me if I haven't seen the
device before. On the other hand, if I connect my own drives, it makes
sense to call them by their serial numbers or something like that.

I think that it's clear from all this, that device naming is a matter
of policy and that the best the OS can do is to give the users a way
how to specify their policy, which is what udev does.

				Have a nice fortnight
-- 
Martin `MJ' Mares   <mj@ucw.cz>   http://atrey.karlin.mff.cuni.cz/~mj/
Faculty of Math and Physics, Charles University, Prague, Czech Rep., Earth
P.C.M.C.I.A. stands for `People Can't Memorize Computer Industry Acronyms'
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