[LAU] Raspberry: problems with shell script launcher when booting

Hello, dear folks. I'm still (constantly) tweaking my raspberry here and there when I can. I have some configurations/sessions that run ok, Looper (jack+sooperlooper), Looper+Fx (jack+sooperlooper+rakarrack/guitarrix). But I'm still having some annoying problems that wanted to share with you: 1) Simple session script, Looper, runs quite well when launched (via ssh -X or from console) logged as PI user. When I run it as a boot/init script (simple launcher script placed in /etc/init.d and then installed with "update-rc.d launcherscript defaults 99"), almost in every first start there's crackles and noise and my loops sound distorted, even with clean guitar; if I restart then it goes well (2nd or 3d time). 2) Next step forward I added Rakarrack in charge of guitar FX routed to the Looper. First, it happens almost same thing as mentioned about noise. Well, I guess It should have something to do with the signal path and things connected to the same power supplier, so I'll have to reserve some time to debug and switch off things until I get a cleaner signal and get rid of the hum and crackles. But the main issue is that there's problems with Rakarrack not been able to start because several problems with not enough Jack ports and Jack and RT. I didn't have any of these problems before. I got to solve the problem with ports changing -p16 to -p32 when launching jack+sooperlooper (-p24 is enough for just Rakarrack). Then I made a launcher script LSB compliant (service script placed in /etc/init.d and then installed with "update-rc.d servicescript defaults", with LSB flags and functions for "start" and "stop", as a proper newer Debian service, and configured to launch last in boot phase) which then call the Jack-config+Rakarrack+Sooperlooper session launcher script. I can see on screen in the init messages this error: "JACK is running in realtime mode, but you are not allowed to use realtime schedule..." But I know RT is already configured, so I guessed it was something to do with the boot/init stage configuration and environment. I tried using "su" with several different parameters to run the launcher script as "pi" user, as It runs quite well when logged as this user (calling just the script and even with "sudo /etc/init.d/script start"). So, maybe you can't get RT in init phase on RaspberryPI and you can only when you get to the login prompt and everything is loaded and ready. But I think there's a "Puredata on Raspberry PI" project that runs some scripts in the init stage; and it seems that in order to get a headless FX+looper station, running some configuration+apps-launcher at boot time is an obvious choice. I'm sure something escapes me after so much try-error-code cicles. Maybe you have some ideas. Thanks as always. -- Carlos sanchiavedraz * Musix GNU+Linux http://www.musix.es