When I run audacity in my mandarake 10.1 linux, I receive the message:

There was an error acessing the I/O shell. There won't possible audio read/write

Error: Host error

If I hit a "ps a" command in the konsole the processes listed don't include anyone that suggest to be using any audio feature.



Ricardo
Sao Paulo - Brazil

I've posted the same questions some days later and a polland guy give a response that seems to doesn't solve the problem...

this can be two things
permissions
please post output from
ls -l /dev/dsp
and the output from
grep audio /etc/group
or there is a sound daemon running
please post output from
ps -C esd
and
ps -C artsd

ps a
i don't think is going to tell you what you need to know

Below the output from the commands you ask me for. Hope you can find the trouble...
Thank you very much...

>this can be two things
>permissions
>please post output from
>ls -l /dev/dsp
[ricardo@localhost ricardo]$ ls -l /dev/dsp
crw-rw---- 1 ricardo audio 14, 3 Jul 21 20:40 /dev/dsp
[ricardo@localhost ricardo]$
=============
>and the output from
>grep audio /etc/group

[ricardo@localhost ricardo]$ grep audio /etc/group
audio:x:81:
[ricardo@localhost ricardo]$
=============
>or there is a sound daemon running
>please post output from
>ps -C esd
>and
>ps -C artsd

[ricardo@localhost ricardo]$ ps -C esd
PID TTY TIME CMD
[ricardo@localhost ricardo]$
[ricardo@localhost ricardo]$ ps -C artsd
PID TTY TIME CMD
4316 ? 00:00:05 artsd
[ricardo@localhost ricardo]$
=============
>ps a
>i don't think is going to tell you what you need to know

[ricardo@localhost ricardo]$ ps a
PID TTY STAT TIME COMMAND
3922 tty1 Ss+ 0:00 /sbin/mingetty tty1
3923 tty2 Ss+ 0:00 /sbin/mingetty tty2
3924 tty3 Ss+ 0:00 /sbin/mingetty tty3
3925 tty4 Ss+ 0:00 /sbin/mingetty tty4
3926 tty5 Ss+ 0:00 /sbin/mingetty tty5
3927 tty6 Ss+ 0:00 /sbin/mingetty tty6
4358 pts/2 Ss 0:00 /bin/bash
4409 pts/2 S 0:00 /bin/sh /usr/bin/firefox
4428 pts/2 S 0:00 /bin/sh /usr/local/src/firefox-installer/run-mozilla.
4433 pts/2 Sl 0:58 /usr/local/src/firefox-installer/firefox-bin
4702 pts/2 R+ 0:00 ps a
[ricardo@localhost ricardo]$

you got that kde sound server artsd running
you can do a few things to fix
1) (temporary) kill it
kill -C artsd
then start audacity

2) (permanent) go into kde controll and uncheck "enable sound system" restart kde

Done!

Thank you very much!

It will be therefore so usefull if you'll explain what had happen... By this way we all will learn more about linux and its sound system...

when you run a sound server like artsd , esd, jack
the sound server takes controll of and holds a lock on the sound system
all applications that need the sound system then have to output to the sound server.
this is often done through a plugin like in xmms.

audacity is very old and only supports direct OSS output and can't go through the sound server.
it just reads from and dumps to /dev/dsp

Linux sound has evolved alot from oss and arts/esd (arts was the first software mixing and sound polling)
to ALSA (which can do it's own sofware mixing and provides OSS emulation) and a new advanced sound server JACK

different applications can use different aspects of it all and there is still no standard
someday there may evolve a standard all applications can use and things will be easier.

i think kde will eventually drop arts