udev Configuration in debian

What is udev?

udev - /dev/ and hotplug management daemon

udev is a daemon which dynamically creates and removes device nodes from /dev/, handles hotplug events and loads drivers at boot time. It replaces the hotplug package and requires a kernel not older than 2.6.12.

Install udev in Debian

#apt-get install udev

After installing this you need to reboot your machine.

Upgrade from devfs to udev on Debian Sarge

Some of you used devfs under Woody, or under their previous Sarge install. When going kernel 2.6, it may be useful to revert or upgrade to udev instead. The problem is that their nomenclatura is different, so your system may be rendered unbootable. Let's see what to care about to switch from devfs to udev.

First, the bootloader will no longer need the devfs=mount parameter on the kernel command-line. So, wheter you use GRUB or LILO, remove or comment the reference to devfs=mount.

Second, check in your /etc/fstab that you have nothing in devfs-nomenclatura, like /dev/ide/host0/bus0/target0/lun0/part3, but everything in the standard nomenclatura like /dev/hda3.

Third, install the udev package, it will probably bring some dependencies too. That's ok.

Last, check the links in /etc/udev/rules.d/. There are probably two links to the upper directory: compat-full.rules and devfs.rules. Remove them and create a new link to udev.rules and to cd-aliases.rules like this

# cd /etc/udev/rules.d/
# rm compat-full.rules devfs.rules
# ln -s ../udev.rules .
# ln -s ../cd-aliases.rules .

Now, reboot, and if you want, remove package devfsd.

Note: It may also be necessary to reconfigure some special packages which store device information in their configuration file, like XFree86.