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Procedure on mounting USB/hotplug devices



No, this is NOT yet another "my USB doesn't work" e-mail. :-)

I only want some info (possibly a link?) from someone knowledgeable on the 
details of what exactly happens (or should happen) from the point of plugging 
in the hotpluggable drive to the point when data can be read from it.

As far as I understand the procedure so far, there are several steps involved 
(please correct me):

1) The device gets plugged in. The USB hardware sees it and sends an 
interrupt. This gets to the kernel.
2) The kernel examines the details of the device, loads appropriate modules 
and instructs udevd (or is it hal?) to create a device node in /dev. This 
gets logged in /var/log/messages.
3) Then udevd (or hal? or what?) creates the device node, and also logs this 
in /var/log/messages. After that, it sends a signal to the next service that 
there is a new device node attached (is this true?).
4) This next daemon/service (which one??? autofs?) catches this signal, reads 
off the device's label (if it has one), creates a new directory named
/media/label and modifies /etc/fstab accordingly so that /dev/device can be 
mounted to /media/label. It also sets the permissions in some way (how??? 
where does one configure them?). It then sends a signal to a possibly-working 
service in a desktop environment (KDE or Gnome) that there is a new device to 
be mounted. 
5) The appropriate DE service gets that, invokes "mount /media/label" (or 
gnome-mount? is that DE-dependant? what if there is no DE running, just a WM 
like WindowMaker? or no X at all?), and after the mount, it puts an 
appropriate icon on the desktop where a user can "click" to open a file 
manager and read/write the data or whatever.

That's about it, AFAIK. Someone fill in the details?

I'd also be grateful for the names of the config files of all those services 
involved, so that I can make my F7 bahave as I want it to. BTW, is this 
behavior the same through distributions? I collected these "steps" based on 
my experience with FC4 (and intuition, logical reasoning, info from the list, 
etc...),  so did it change up to F7 or not (and should it)?

As a side note, "my usb won't mount" problem can appear at any of these steps, 
due to a lot of reasons. It is not always the fault of the kernel, as some 
other threads here usually suggest. That is partly my motivation for this 
post. Also, I believe we could all learn something from the answers... ;-)

Anyone?

Best, :-)
Marko

Marko Vojinovic
Institute of Physics
University of Belgrade
======================
e-mail: vmarko phy bg ac yu


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