jack issue

Installation & Configuration Linux
#1

I recently emerged Ardour to my gentoo, but its giving me that sad “could not start JACK” message, which goes like:

There are several possible reasons:

  1. You requested audio parameters that are not supported…
  2. JACK is running as another user.

Please consider the possibilities, and perhaps try different parameters.

Now when I run qjackctl and hit START, it stops and give me the message.

15:58:36.248 Patchbay deactivated.
15:58:36.267 Statistics reset.
15:58:36.269 Could not open ALSA sequencer as a client. ALSA MIDI patchbay will be not available.
ALSA lib seq_hw.c:457:(snd_seq_hw_open) open /dev/snd/seq failed: No such file or directory
15:58:58.994 Startup script…
15:58:58.994 artsshell -q terminate
sh: artsshell: command not found
15:58:59.397 Startup script terminated with exit status=32512.
15:58:59.397 JACK is starting…
15:58:59.397 /usr/bin/jackd -R -dalsa -dhw:0 -r48000 -p1024 -n2
jackd 0.118.0
Copyright 2001-2009 Paul Davis, Stephane Letz, Jack O’Quinn, Torben Hohn and others.
jackd comes with ABSOLUTELY NO WARRANTY
This is free software, and you are welcome to redistribute it
under certain conditions; see the file COPYING for details
JACK is running in realtime mode, but you are not allowed to use realtime scheduling.
15:58:59.404 JACK was started with PID=9700.
Please check your /etc/security/limits.conf for the following lines
and correct/add them:
@audio - rtprio 100
@audio - nice -10
After applying these changes, please re-login in order for them to take effect.
You don’t appear to have a sane system configuration. It is very likely that you
encounter xruns. Please apply all the above mentioned changes and start jack again!
15:58:59.407 JACK was stopped with exit status=255.
15:58:59.407 Post-shutdown script…
15:58:59.408 killall jackd
jackd: no process found
15:58:59.815 Post-shutdown script terminated with exit status=256.
15:59:01.451 Could not connect to JACK server as client. - Overall operation failed. - Unable to connect to server. Please check the messages window for more info.

I’m selecting USB audio #1 as an interface, which stands for my M-AUDIO FAST TRACK PRO.

So I dont know whats crashing at all. Im reaally new to this, so any kind help would, uum, help. =)

#2
JACK is running in realtime mode, but you are not allowed to use realtime scheduling.
Please check your /etc/security/limits.conf for the following lines and correct/add them: @audio - rtprio 100 @audio - nice -10 After applying these changes, please re-login in order for them to take effect.

There are many many threads on this forum and on countless others describing how to fix this problem.

#3

True. Sorry about that. Working fine.

#4

And, as always, the nice entry does not matter for realtime audio.
However you probably want to add “@audio - memlock unlimited” or something similar.
If you can, please notify the gentoo person responsible for the ebuild.

See http://jackaudio.org/faq

#5

@peder I believe the messaging comes from Jack itself, unless you were saying the ebuild should do those things automatically?

In any case the version of Jack I believe is slightly out of date as the newer versions I think have the correct messaging in there IIRC.

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