In a headless server running Ubuntu 10.04 desktop edition, when trying to launch alsamixer (from terminal) I’ve got an error: alsamixer cannot open mixer: No such file or directory
Using sudo alsamixer is working, therefore I have a clue that this is due to wrong permissions. To check that, issue:
ls /dev/mixer -l
and the result should looks like:
crw-rw---- 1 root audio 14, 0 2011-01-20 22:52 /dev/mixer
then check if your username belong also to this group (audio) with
If your username don’t belong also in the
audio group, you should add your user as a member of it, like
sudo usermod -a -G audio your_login_name
your_login_name with your real login name, logout, login back and alsamixer should work.
– UPDATE –
The above works also in Ubuntu server 12.04 LTS, except that the directory is no longer
/dev/snd. It’s content belong to audio group.