one solution for: /dev/dsp cant be opened no such device Fedora Core 2
hope this could be helpful for somebody else.
I've installed Fedora Core 2, with KDE 3.2, on a PC with mobo PCChips and a sound card Crystal Sound cd4281.
From the time I boot up and start KDE, I got the message from aRts:
Error while .......... /dev/dsp cant be opened, no such device.
Sound server will continue with the /dev/null output.....
During installation soundcard was autodetected and configured ok, but no sound was played.
After running sound card detection utility (hat->System configuration-> sound card detection) sound came up correctly but with any reboot the same problem re appear.
Tried a lot of things (updating libgnome, changing .kmcartsrc, changing permissions to /dev/dsp, installing arts-devel, etc) but nothing worked.
Finally using at the prompt of a command line terminal (as root):
obtained a list of modules present.
I did it before running the sound card detection, and then repeated it after s.c. detection.
That showed that some modules were loaded with this utility that were not loaded during startup, causing the problem.
So I've added to my /etc/rc.d/rc.local the lines showed below ( extra modules loaded by s.c. detection utility):
this loaded all those modules during startup and the problem dissapeared.
Maybe other systems require some other modules to be loaded in order to aRts working properly, then you should run /sbin/lsmod immediately after startup (with the problem) and then after s.c. detection (without the problem) and list all the new modules in order to add them to your rc.local.