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I rarely use DVD's, so I just noticed that VLC couldn't find the drive (as /dev/dvd ). Looking into /dev folder, /dev/dvd1 and /dev/dvdrw1 and /dev/cdrom1 exist. I never had a second dvd drive in there, so my question is:

How did that happen?

What is responsible for assigning those devicenames?

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up vote 2 down vote accepted

I can't say how but the udev rules is assigning those devicenames. In the past, with the Kubuntu:

A readme: /etc/udev/rules.d/README

The files in this directory are read by udev(7) and used when events are performed by the kernel. The udev daemon watches this directory with inotify so that changes to these files are automatically picked up, for this reason they must be files and not symlinks to another location as in the case in Debian.

Packages do not generally install rules here, this directory is for local rules. If you want to override behaviour of package-supplied rules, which can be found in /lib/udev/rules.d, you can do one of two things:

1) Write your own rules in this directory that assign the name, symlinks, permissions, etc. that you want. Pick a number higher than the rules you want to override, and yours will be used.

2) Copy the file from /lib/udev/rules.d and edit it here; you should generally only do this if you want to prevent a program from being run.

If the ordering of files in this directory are not important to you, it's recommended that you simply name your files "descriptive-name.rules" such that they are processed AFTER all numbered rules in both this directory and /lib/udev/rules.d and thus override anything set there.

The /etc/udev/rules.d/70-persistent-cd.rules has the CD and the DVD rules. You could modify it:

This file was automatically generated by the /lib/udev/write_cd_rules program, run by the cd-aliases-generator.rules rules file.

You can modify it, as long as you keep each rule on a single line, and set the $GENERATED variable.

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Ah, thanks for the info! I think I found out why it's cdrom1 etc - I have a 3g-usb stick with onboard flashdrive which mounts as "CDROM" (in Windows, contains drivers). Somehow this preceded the DVD drive on install. – marto Dec 22 '11 at 20:08
Accepted above answer for pointing me at the /etc/udev/rules.d/70-persistent-cd.rule file (which caused the problem) – marto Dec 22 '11 at 20:13
After modifying the file, you can type sudo udevadm trigger to re-create the correct links without rebooting. – akaihola Apr 21 '12 at 8:14

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