Difference between revisions of ""arecord: ... audio open error: Device or resource busy""
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</pre> | </pre> | ||
This puzzled me for a while because I couldn't see anything obvious running on my laptop. | This puzzled me for a while because I couldn't see anything obvious running on my laptop. | ||
| − | I figured some kernel thing had left something lying around. But I didn't see any defunct zombie processes running. So the process was still running or the kernel itself had the sound hardware reserved. | + | I figured some kernel thing had left something lying around. But I didn't see any defunct zombie processes running. So the process was still running or the kernel itself had the sound hardware reserved. I used '''fuser''' to see what was using anything under '''/dev/snd/*'''. |
<pre> | <pre> | ||
| − | + | # fuser -fv /dev/snd/* | |
| − | |||
USER PID ACCESS COMMAND | USER PID ACCESS COMMAND | ||
/dev/snd/controlC0: root 843 F.... pulseaudio | /dev/snd/controlC0: root 843 F.... pulseaudio | ||
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</pre> | </pre> | ||
| − | I don't know how pulseaudio got started and I don't know how I did not notice it running. Fortunately that what '''fuser''' was made for. | + | I don't know how pulseaudio got started and I don't know how I did not notice it running. Fortunately that what '''fuser''' was made for. The fact that all the pcm devices were mmap'ed is what was locking the audio device. |
Latest revision as of 00:29, 14 January 2019
When trying to record some sound from the command-line you see an error message like this:
# arecord -d 5 -f S16_LE -r 44100 -D plughw:2,0 test.wav arecord: main:828: audio open error: Device or resource busy
This puzzled me for a while because I couldn't see anything obvious running on my laptop. I figured some kernel thing had left something lying around. But I didn't see any defunct zombie processes running. So the process was still running or the kernel itself had the sound hardware reserved. I used fuser to see what was using anything under /dev/snd/*.
# fuser -fv /dev/snd/*
USER PID ACCESS COMMAND
/dev/snd/controlC0: root 843 F.... pulseaudio
/dev/snd/controlC1: root 843 F.... pulseaudio
/dev/snd/controlC2: root 843 F.... pulseaudio
/dev/snd/pcmC0D0p: root 843 F...m pulseaudio
/dev/snd/pcmC1D0c: root 843 F...m pulseaudio
/dev/snd/pcmC2D0c: root 843 F...m pulseaudio
/dev/snd/pcmC2D0p: root 843 F...m pulseaudio
I don't know how pulseaudio got started and I don't know how I did not notice it running. Fortunately that what fuser was made for. The fact that all the pcm devices were mmap'ed is what was locking the audio device.
