Jack problem with mackie profx8

16:02:14.268 JACK démarre...
16:02:14.269 /usr/bin/jackd -P70 -dalsa -r48000 -p512 -n3 -D -Chw:2,0 -Phw:2,0
Cannot connect to server socket err = Aucun fichier ou dossier de ce type
Cannot connect to server socket
jack server is not running or cannot be started
16:02:14.277 JACK a été démarrer avec le PID=17928.
no message buffer overruns
no message buffer overruns
jackdmp 1.9.7
Copyright 2001-2005 Paul Davis and others.
Copyright 2004-2011 Grame.
jackdmp 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 server starting in realtime mode with priority 70
control device hw:2
control device hw:2
audio_reservation_init
Acquire audio card Audio2
creating alsa driver ... hw:2,0|hw:2,0|512|3|48000|0|0|nomon|swmeter|-|32bit
control device hw:2
the playback device "hw:2,0" is already in use. Please stop the application using it and run JACK again
Cannot initialize driver
JackServer::Open() failed with -1
Failed to open server
16:02:14.372 JACK a été arrêté avec statut de sortie=255.
16:02:16.317 Impossible de connecter le serveur JACK comme client. - L'opération a échoué. - Incapable de se connecter au serveur. Veuillez consulter la fenêtre des messages pour plus d'informations.
Cannot connect to server socket err = Aucun fichier ou dossier de ce type
Cannot connect to server socket
jack server is not running or cannot be started