[NTLUG:Discuss] Where do USB devices appear these days?

[Chris Cox]

steve wrote:
> I just recently upgraded to SuSE 9.3 from 9.1 and I find that my
> USB devices don't work like they used to.
> 
> I'm a pretty dedicated command-line person - so I dislike pointy-clicky
> things.
> 
> In the past, it was all very logical - I plugged in my camera or my
> USB thumb drive or hard drive - and a few seconds later, the device
> would be automounted in /media - easy.

SUSE USED to suse their own form of hotplugging.

> 
> Now, one of about four things happens:
> 
> 1) Nothing.

Ok.

> 
> 2) The device DOESN'T appear in /media - and the KDE file manager
> thingy pops up (totally un-asked-for) and tells me that my camera
> is in:
> 
>     camera://Olympus_whatever/

That's a KDE feature... with my Olympus, trying to navigate
through that window crashes the window :)

> 
> 3) It appears in /media but the popup thingy doesn't appear.

Hmmm...


> 
> 4) It appears in /media AND the popup thingy appears.

Hmmm...

> 
> It's weird.
> 
> But what is this URL-like "camera://" thing?  Whatever happened
> to filenames and paths and such?   I presume this is just a
> thin veneer of cuteness over the underlying file system - so
> where *is* 'camera://'.
> 
> I *hate* this ongoing cute-ification!

You can blame the kernel and udev for most of this.  With SUSE 9.3,
SUSE moves away from their way of doing hotplugging (much to
the rejoicing of the the non-SUSE crowd.. which is loud and
vocal) and on to udev.  But udev was pretty shaky at that
point.. not that it is a whole lot better in 10.0 (btw).
I think Mandrake (or whatever they like to be called now) used
devfs... which is also now deprecated.

Ideally, the appropriate rules should get fired off when the
device is plugged in and the appropriate submount is made
under /media (SUSE uses submount).

It works for my Olympus camera under SUSE 9.3, but the
KDE camera: support doesn't work (but I get both
pop ups).

Hot plugging of devices and automounting still needs some
work.  I'm not convinced all of the kernel generic
support is all that great.  I know a lot of people
hated SUSE's prior approach.... but they had a hot plug system
that worked a long time before anyone else did.  I feel
like we're taking a few steps backward with the
distribution agnositic hotplug support.... but it will
get better over time.  There were certain cases where
SUSE's old hotplug support didn't work right either (so
the other dists would point the finger and say... well
it's a SUSE problem with THEIR hotplug support... it
sucks... and so on and so on).

udev is a pretty mysterious thing.

Here's some links:
http://www.kernel.org/pub/linux/utils/kernel/hotplug/udev.html
http://www.kernel.org/pub/linux/utils/kernel/hotplug/udev-FAQ
http://www.linuxjournal.com/article/7316
http://support.novell.com/techcenter/sdb/en/2004/05/91_coldhotplug.html

Note:  Novell's knowledgebase/coolsoln's etc. don't generally
have specific version numbers... so it's hard to figure
out what document applies to what version of SUSE.