Re: [gentoo-amd64] Please get me straight about sysvinit vs. systemd, udev vs eudev vs mdev, virtuals and other things...

[Frank Peters <frank.peters@comcast.net>]

On Mon, 3 Mar 2014 11:20:50 -0800
Mark Knecht <markknecht@gmail.com> wrote:

> 
> While I understand your point these two comments contradict each
> other, or more accurately, the first was inaccurate in the sense that
> someone needed to create your /dev entry, either udev or you, it
> didn't matter. Once it was there your scanner worked, correct?
> 

With USB devices things are a bit different.  If I plug in a USB
gadget, the kernel will report a certain device.  If I then unplug
it and then immediately replug it, the kernel will report a different
device even though it is the same USB gadget.  For this reason, udev
can alleviate the uncertainty by automagically constructing the
correct device node.

However, until recently, USB scanners were accessed through a kernel
module and this allowed a static node to be created in the /dev tree.
Using the kernel module access, SANE could always find the scanner.
For some reason, the scanner module has been eliminated from the
kernel and now udev is unconditionally necessary for scanner access
(unless the user employs an awkward workaround).

This represents the future trend.  Udev will be an absolute, total
requirement for everything.

Admittedly, my views are in the (exteme?) minority.  So it's goodbye
simplicity and hello complicated junk.

I used to have a lot of fun building and tweaking my Linux system,
but that experience is fading fast.

Frank Peters