++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++ +++ +++ ____ __ __ ____ _ _ ____ ___ +++ +++ | _ \ ___| \/ |_ _| _ \(_) / | |___ \ / _ \ +++ +++ | | | |/ _ \ |\/| | | | | | | | | | | __) || | | | +++ +++ | |_| | __/ | | | |_| | |_| | | | |_ / __/ | |_| | +++ +++ |____/ \___|_| |_|\__,_|____/|_| |_(_)_____(_)___/ +++ +++ +++ +++ +++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ DeMuDi 1.2.0 FAQ ================ Frequently Asked Questions about installing and configuring AGNULA/DeMuDi 1.2.0 1. Configuration 2. Network 3. Permissions & ALSA 4. JACK Audio Connection Kit 5. Xruns, interupts, hdparm & runlevels 7. Unresolved issues 8. Upgrading existing installations 9. Package updates 10. Further help 1. Configuration ================ Assuming you've followed all installation instructions so far, you'll now be gazing at a blank fluxbox or GNOME destop depending on whether you chose the 'minimalistic' or'user friendly' interface during installation, but little of it works, at least, not the way you want it to. If you haven't even got that far, you may need to do a little troubleshooting first. Choose an XShell you're comfortable with. If you've not used a text interface before (i.e. new to GNU/Linux) spend a while getting used to it, you're going to need it. Commands prefaced by a $ are to be entered as a normal user, commands with a # in front of them need to be entered as root, this is your prompt (You don't need to type it). To get access to root type: $ su this will ask you for root's password and then allow you to execute commands as root. # exit will return you to a normal user. Don't stay logged in as root and pay careful attention to what you are doing (write it down, even), mistakes here are often difficult to resolve, you have been warned! If you want to know more about any of the commands type man at the prompt. Q: The X Window graphical systems fails to start A: This is probably due to your video card not being properly detected. You may need to google a little bit to find out if your video card is supported and which is the right module for it. Note also the NVidia cards need propertary drivers which can be found in the non-free section of Debian. Detailed instructions can be found here: http://lists.agnula.org/pipermail/users/2004-September/003171.html Q: I can't get a picture to display at all and my mouse doesn't work A: You can reconfigure the X server with the command # dpkg-reconfigure xserver-xfree86 or # xf86config Q: At boot no splash image appears and the boot loader looks crappy A: You've probably created a separate partition for /boot, so that the splash image can't be found. Please either move /boot to the root / partition, or change the paths in /boot/grub/menu.lst accordingly. 2. Network ========== The installer should configure the network for you. If for some reason that hasn't happened then you will need to configure the network by hand. If you use dial-up or PPPOE or something, use pppconfig or pppoeconf. If you use DHCP, please become root and run # apt-get install etherconf Then follow the instructions, and when asked for a domainname, leave the field empty. If you're on a laptop you may need to configure pcmcia-cs before this will work. As this is a GNU system, there are several different methods you could use for configuration. If you have a preferred method of setting up your network it should also be available and you can always edit /etc/network/interfaces by hand. The information you need to do this is at: # man 5 interfaces You can then bring the network up with: # ifup eth0 or whatever interface you are using instead of eth0. As soon as you're online, open up a web browser and read these: http://www.agnula.org/documentation/FAQ/ http://www.alsa-project.org/alsa-doc/ http://www.debian.org/doc/manuals/reference/reference.en.html http://d-i.alioth.debian.org/manual/en.i386/index.html http://kreiger.linuxgods.com/kiki/?linux+sound-permissions 3. Permissions & ALSA ===================== Check that you have the necessary permissions to use the audio devices. vi is used for some of these examples, but again, your favourite text editor will do fine. Make sure your username is in this file next to the audio entry. It should be, by default, so you shouldn't need to change anything here. $ cat /etc/group If you need to add yourself to the list you can use this command: # useradd -G audio username In order to get alsa to function properly you may need to edit /etc/alsa/modutils/1.0 and/or /etc/modutils/alsa-base then: # update-modules and also $ vi ~/.asoundrc notice that last command is in your home directory so you don't need to be root, so you shouldn't be ;-). See the ALSA website for further details on what to put in these files. To to check that everything is set up right just run: /usr/sbin/aadebug The script will also provide some useful info to accompany any further questions. You will need a little knowledge of how BASH scripts work to use this. If you look in your menu; Apps > System > Admin has some useful tools such as alsaconf, if your soundcard failed to autoconfigure. You may need to create the file /etc/alsa/modutils/1.0 by hand before this will work. /etc/modutils/alsa-base should be a duplicate of this file. If not copy it across and don't forget to update-modules. You may need to log out & back in before these changes take effect. 4. Getting to Know JACK ======================= OK, so that's the basic set-up, now you should be hearing some recognisable sound. To check that it's all working properly, it's probably best to go through the exercises in the First steps in Agnula tutorial. QJackCtl Now you've done that, it's time to have a look at qjackctl, that funny little control panel sitting in the middle of your desktop. Hopefully it's already running, if not hit the Start button. All being well you'll see the word Started come up in the window with 0 (0) below it. Click on the Connect button and it should show alsa_pcm in both the input and output windows. If so, you're ready to make some music. If you need to alter the way Qjackctl and gkrellm start up look in: # cat /etc/X11/Xsession.d/51demudi. If it's not all gone so smoothly, click on Messages, if you see anything much more complicated than: 20:19:41.579 Client activated. 20:19:41.583 Audio connection change. 20:19:41.617 Audio connection graph change. then you're going to need to do some work to get the best out of this. If you only want to use one application at a time, you may not need to worry about JACK too much right now. However, if you want the full power of a Linux Audio system then it's worth taking the time to figure this out. The Status button also provides some slightly less verbose information. Setup Settings tab The 'Server Path' should be set to jackstart and the 'Driver' to alsa. 'Parameters' - you probably want to check Realtime for most work and Softmode to start with. 'Softmode' means that JACK doesn't quit if you get odd xruns, obviously, you won't want this if you're recording. If you know your machine only works at 16bit resolution check Force 16bit. You'll probably want to leave most settings where they are. If you're operating in realtime, your 'Priority' should usually be 0, but some soundcards differ. 'Frames/Period' worth setting at the maximum to start and then working your way down. This setting affects your latency most directly, setting it too low will result in xruns. 'Sample Rate' probably wants to be 44100 (CD quality) but some soundcards prefer 48000 (DAT quality). 'Periods/Buffer' almost certainly wants to be 2, but again, your soundcard may vary. ;-) 'Interface' - probably should be hw:0 or whatever you specified in your ~/.asoundrc. 'Audio' try 'Playback' only if you're having trouble, mostly you'll want full Duplex. 'Dither' - 'Shaped' is best but CPU hungry, 'Triangular' gives a good compromise, you don't _need_ dithering, so None will do for now. 'Timeout' and 'Start Delay' you might want to consider increasing these in certain situations. OK your new settings Stop if JACK is still running and Start again. You may need to play with the settings a bit to get satisfactory results. 5. Xruns ======== During recording sessions, the Messages panel in Qjackctl may report xruns. Xruns are basically an indications that while Jack is running something gets in the way of it running correctly and it becomes unable to cope with the flow of data causing dropouts in the sound. Let's look at the possibilities: Interrupts If some other card has a higher priority then when it generates an interrupt, if it's slow responding, then possibly Jack and the sound card cannot get their job done. # cat /proc/interrupts and # lspci -v will give you some valuable information here. Generally speaking, you want your soundcard to be in the highest priority slot (9 or 10) and not sharing with anything. Solutions mostly involve physically moving the soundcard up to a higher slot and/or disabling unused hardware in the BIOS. Hard drive speed is too slow # hdparm -tT /dev/hda (or whatever drive you use for audio) A/DeMuDi installs with optimal settings for most drives. You shouldn't need to edit /etc/hdparm.conf unless you know you do. You can cause irreversible data corruption messing with these settings. Read: # man hdparm before you attempt anything. Too many processes running Processes that interrupt system operation on a regular basis can also cause xruns, although technically this shouldn't be a problem for a powerful enough machine running a low-latency kernel. $ ps fax will show you all the processes currently running on your box. One way of cutting down on running processes is to specify a runlevel that is reserved for making music, for example /etc/rc5.d, the default runlevel is /etc/rc2.d. These directories contain links to the scripts that start & stop essential services, usually when you boot up and shut down. Each of these links starts with S##, change the non-essential services to K## using your favourite runlevel editor (again, plenty of choice). Likely candidates for removal are anacron, klogd & cron, most are inessential apart from the obviously music related ones. You can then change runlevels by issuing: # telinit 5 or whatever level number you chose. It's also worth disabling your screensaver and generally closing down any unused applications or XShells. You can automate this process in the Options tab of Qjackctl's Setup dialog to execute the appropriate commands on startup and shutdown. 6. Further Reading ================== http://www.linuxdj.com/audio/quality/ http://jackit.sourceforge.net/docs/faq.php http://alsa.opensrc.org/ http://linux-sound.org/ 7. Unresolved Issues ==================== There's Just One Other Thing ... Q: I've got unresolved symbols! A: Yeah, we know. depmod:*** unresolved symbols in /lib/modules/2.4.25-1-multimedia-686/kernel/drivers/media/radio/micropcm20.o depmod:*** unresolved symbols in /lib/modules/2.4.25-1-multimedia-686/alsa/sndpdaudiocf.o depmod:*** unresolved symbols in /lib/modules/2.4.25-1-multimedia-686/alsa/snd-vx-cs.o depmod:*** unresolved symbols in /lib/modules/2.4.25-1-multimedia-686/alsa/snd-440.o depmod:*** unresolved symbols in /lib/modules/2.4.25-1-multimedia-686/alsa/snd-vxpocket.o You can safely ignore all these messages. The last four are because you haven't installed pcmcia-modules. Q: I think I forgot to configure something else. A: If you're worried you've missed something out, # dpkg-reconfigure -a Will take you through the configurations of all packages. This will take some time and concentration. 8. Upgrading existing installations =================================== Q: Can I upgrade my existing 1.2.0-beta0 installation? A: Yes, please read the Package Updates section below. Q: Can I install A/DeMuDi over an existing Debian installation? A: Yes, at least as long as you are running Sarge. Follow the following steps * become root * edit your /etc/apt/sources.list adding deb http://apt.agnula.org/demudi testing main local extra * from the command line issue: # apt-get install demudi-install demudi-base * install the tasks you are interested in; to have a look at them * run: # apt-cache search demudi the task demudi installs them all * install the appropriate kernel for your processor: # apt-get kernel-image-2.4.25-1-multimedia- where might be 386, 586tsc, 686, k6, k7, and the relevant ALSA modules too: # apt-get install alsa-modules-2.4.25-1-multimedia- * finally you may want to run some customisation scripts which * automatically tune your system: # cfagent-demudi -D postbaseconfig -D upgrade Q: Can I upgrade my existing 1.0/1.1.0 installation? A: Yes, using apt. See more info on upgrading. Q: Can I upgrade my existing 1.1.1 LiveCD installation? A: No cannot upgrade a 1.1.1 LiveCD install. It was not meant for hard disk installation, but only for demo porpoises. Q: Is this a LiveCD? A: No. It requires installation to your hard drive. 9. Package Updates ================== At some point you may want to update your packages in order to take advantage of upgrades, new software or bug fixes by using Debian's wonderful tool apt (this requires a network connection). Many people like to use a package manager such as dselect or aptitude, if you prefer a point & click GUI, synaptic is very useable. To configure apt to grab packages from the network, we need to edit /etc/apt/sources.list. Here is the whole file, but note that the only changes you need to make are uncommenting the two bottom lines, and changing the next-to-last entry to say "testing main local extra". # cat /etc/apt/sources.list deb cdrom:[aGNUla/DeMuDi 1.2.0-beta2 - # i386 Binary-1 (20040620)]/ unstable local main deb # cdrom:[aGNUla/DeMuDi 1.2.0-beta2 - i386 Binary-1 (20040620)]/extra/ # unstable main deb http://apt.agnula.org/demudi/ testing main local # extra deb http://snapshot.debian.net/archive/2004/07/14/debian/ # testing main contrib non-free Now that apt is configured, let's get all the updated packages: # upgrade-demudi 10. And beyond ... =================== Next you'll be wanting to try out some of these wonderful Linux Audio applications, so we'll leave you in the capable hands of Dave Phillips and his excellent Tutorials. If by some strange chance you find a bug ;-) please submit a bug report at the development GForge portal. If you want to discuss this FAQ or write a HOW-TO yourself, log in to aGNUlaWIKI and make a contribution. Subscribe to the mailing lists and let us know what you think. Other previously answered questions are available at the mailing list archives. Yes, this is a hint. ;) Make some great music!