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[alpine-devel] Re: udev replacement on Alpine Linux

From: Jude Nelson <>
Date: Sat, 25 Jul 2015 20:51:12 -0400

Hi everyone,

> [vdev] a device manager with an approach a bit different, offers an
> optional filesystem interface that implements a per-process view of
> /dev. Possibly the least simple alternative, but interesting
> nonetheless.
Thank you for your interest in vdev. I am the principal developer. I hope
you all don't mind me chiming in to provide a little bit more information.

First, I can't emphasize the "optional" qualifier enough regarding the
filesystem component vdevfs. The hotplug daemon vdevd and the
libudev-compat library are meant to replace udevd and libudev respectively;
the filesystem is an add-on that can be used independently of whatever
device manager is running. There are more detailed write-up's on the
design goals for each of the three vdev components in [0] and [1].

Second, I would like to point out that vdevd by itself is not too different
from mdev, nldev, and smdev. The udev-like behavior comes almost entirely
from the shell scripts and auxiliary helper programs it executes in
reaction to device uevents. I bring this up because these scripts and
helper programs could easily be ported to mdev, nldev, and smdev simply by
providing a wrapper that sets the appropriate environment variables (a
listing can be found in Appendix A of [2]).

Third, I would like to point out that libudev-compat is *not* dependent on
vdevd or any device manager. A libudev-compat process receives device
events by watching for new files written into a well-defined directory in a
RAM-backed filesystem. Vdevd simply runs a script to fill in /run/udev and
write device event files in order to communicate with libudev-compat

I'm happy to help test and evaluate vdev with Alpine. This document [2]
contains a tutorial on how to try it out without installing, and what to
send me if something breaks. We'll be making an alpha branch soon (see



Received on Sat Jul 25 2015 - 20:51:12 UTC