UDEV Rules Didn't Behave Like I Thought

Ken Moffat ken at linuxfromscratch.org
Tue Mar 7 14:20:32 PST 2006


On Tue, 7 Mar 2006, Dan McGhee wrote:

> This may be long and convoluted,

  I think that goes with the territory (udev), it's still in a state of 
flux.

[...]
> The /dev/dvd symlink was created but the /dev/cdrom symlink was not. The 
> 25-lfs.rules is from UDEV-71.  In my other LFS distro I have UDEV-58 and both 
> symlinks were created.  The only difference is the use of "==" in UDEV-71 and 
> just "=" in UDEV-58.
>
  I'm currently using (lines broken up for mailing)
echo 'BUS=="ide", KERNEL=="hdc", GROUP="audio", 
NAME="%k", SYMLINK="cdrom dvd", MODE="0660", OPTIONS="last_rule"'
   >/etc/udev/rules.d/20-media.rules

  which works for me

ken at bluesbreaker ~ $ls -l /dev/hd? /dev/cdrom /dev/dvd
lrwxrwxrwx 1 root root      3 2006-03-07 20:05 /dev/cdrom -> hdc
lrwxrwxrwx 1 root root      3 2006-03-07 20:05 /dev/dvd -> hdc
brw-rw---- 1 root audio 22, 0 2006-03-07 20:05 /dev/hdc
ken at bluesbreaker ~ $

  I guess the difference is I put the multiple symlinks into a single 
rule.

[...]
> When I ran 'udevstart,' I had the two symlinks but /dev/hdc still had group 
> DISK.

  This is an addition to a running system, so udev was already running ? 
If that's the case, /dev/hdc has already been created with the default 
root:disk ownership.  I have a similar situation - I build all the av 
stuff in a script fairly late in my overall build, and then add my rule 
above.  At that point only root can play DVDs or whatever, but on the 
next boot it is fine - yes, I have belatedly taken to turning desktops 
off ;-)

Ken
-- 
  das eine Mal als Tragödie, das andere Mal als Farce


More information about the blfs-support mailing list