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Frequently asked questions

Fundamentals

Conventions

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, that means you don't need to type it.

Using the shell - The command line interface

If you've not used a text interface before (i.e. are new to GNU/Linux) spend a while getting used to it, you're going to need it. A GUI (Graphical User Interface) is great, but nothing beats a command line terminal for speed and flexibility.

An introduction to the shell, Linux's command-line interface:

Becoming root (the system administrator)

To get access to root type:

   $ su

This will ask you for root's password and then allow you to execute commands as root.

The command:

   # 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!

Man pages

If you want to know more about any of the commands type:

   $ man some_command

at the prompt.

Hardware setup

The X Window graphical system fails to start

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 (driver) for it. Note also the NVidia cards need proprietary drivers which can be found in the non-free section of Debian software archives.

Detailed instructions can be found here.

The new 1.2.1 release will be using Xorg, in which case:

   # dpkg-reconfigure xserver-xorg

   # xorgconfig
   # xorgcfg

The configuration file is located at /etc/X11/xorg.conf - read this file well, you will probably need to modify it manually at some point. Also remenber that if something has been modified manually you need to run the following commands:

   #   cp /etc/X11/xorg.conf /etc/X11/xorg.conf.custom
   #   sudo sh -c 'md5sum /etc/X11/xorg.conf > /var/lib/xfree86/xorg.conf.md5sum'
   #   sudo dpkg-reconfigure xserver-xorg

Previous versions of A/!DeMuDi(<=1.2.0) used the following commands:

   # dpkg-reconfigure xserver-xfree86
   # xf86config

I can't connect to the 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 (PPP over Ethernet) or something, use pppconfig or pppoeconf

To configure the network, make sure you have gnome-system-tools installed. It will appear on the menu as Debian -> Apps -> System -> Network Admin. You can also invoke it from the command line thus:

   # network-admin

The GNOME Network Tool (gnome-nettool) is highly recommended for beginners.

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.

more info

Wireless connections

If your wireless connection was not recognized search for information on the manufacturer's web page about linux drivers (modules), Get the source driver for linux if you can find it. Untar the source and read up on how to install it (./configure-make-make install) or try to use module-assistant. You will need wireless-tools to configure your wireless card, iwconfig mainly.

more info

My ATAPI CD Burner won't work

If you have an IDE cdrom and 2.4 kernel, you will need to pass extra arguments to the kernel at startup time. Say the cdrom is on /dev/hdc, you would append 'hdc=ide-scsi' in the grub menu item.

Debian -> Apps -> System -> Boot Admin

This will help cdrecord to use your cdrom as if it were a SCSI drive. Then cdrecord -scanbus should detect your drive. For further information on this subject have a look at the /usr/share/doc/cdrecord/README.ATAPI.setup file.

A/DeMuDi cannot detect my common DVD or SATA drives

This can happen with some DVD/Rw and SATA hard disks.

Check the settings in your BIOS, some people have found setting the SATA mode to "enhanced" instead of "auto" helped. Some BIOSes can be set to autodetect your disks, you may also find setting the second IDE to "auto" rather than "CDROM" helps with DVD drives.

My soundcard needs some kind of firmware

As ADeMuDi can't distribute non-free firmware, it is sometimes necessary to go and grab the right packages from the internet (again, this may require a little googling) and then follow this procedure:

Check what kernel version you are running:

    # uname -r

Also check what version of ALSA you are using, here we are assuming 1.0.9 - YMMV! You may also need to install the kernel headers that match your kernel.

    # apt-get install alsa-tools alsa-firmware-loaders
    # mkdir ~/ALSA/
    # cd ~/ALSA/

Then download alsa-firmware-1.0.9 into ~/ALSA/ from http://public.planetmirror.com/pub/alsa/firmware and untar and install it:

    # tar -xvjf alsa-firmware-1.0.9.tar.bz2
    # cd ~/alsa-firmware-1.0.9
    # ./configure
    # make
    # make install

You may then need to run the firmware loader, for example for the RME HDSP you would type:

    # hdsploader

There is more info on hdsp cards if you need it. It should be that simple. Live long and prosper!

Fonts don't display properly in my locale

You can solve this by setting a locale under X that does not contain the @euro part. You can check your actual locale settings with the command 'locale'. If you have the '@euro' ending in the locale variables you must delete it in this way (using French as an example):

  $ export LANG=fr_FR

  $ export LANG=fr_FR.UTF-8

(depending on whether you are using utf8 or not, simply use the old value without @euro)

If this works, you can set the LANG variable each time you start X by putting the previous command in your ~/.xinitrc.

You can reconfigure the locales present on your machine with:

  # dpkg-reconfigure locales

and you can set the default locale with (fr_FR should be fine for French users, for example):

  # dpkg-reconfigure localeconf

Boot process

At boot no splash image appears and the boot loader looks crappy

You've probably place /boot in a separate partition of the hard drive, so that the splash image can't be found. Please either move /boot to the root partition (denoted by a single slash: / ), or change the paths in /boot/grub/menu.lst accordingly.

System architecture

Kernel

The latest A/DeMuDi releases use the 2.6 series, with a couple of patches:

to get the sources just set the proper entry in your /etc/apt/sources.list and type apt-get source kernel-image-2.6.12-3-multimedia-386. In particular read the debian/rules makefile to check how the kernel is built.

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 that 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 your chosen window manager starts up, you will need to look at the files kept in /etc/X11/Xsession.d/

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 - the qjackctl settings tab

The 'Server Path' offers you several options, jackstart is for use with 2.4-multimedia kernels and will produce an error under 2.6.

The 'Server Path' should be set to jackd 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.

More information:

   $ zcat /usr/share/doc/jackd/FAQ.gz

Make sure you have:

tmpfs		/dev/shm	tmpfs	defaults        0       0

in your /etc/fstab - it makes a big difference!

ALSA

Configuration

   # alsaconf

How can I verify whether ALSA is enabled in the kernel ?

If you want to know if alsa is already running on your system do 'cat /proc/asound/version' or 'cat /proc/asound/cards'

If this fails, maybe it is installed but not loaded. Try executing /etc/init.d/alsa status as root.

If this fails, then your system is not running ALSA-lib. Besides the kernel options, you need to install and add alsa-lib to your boot sequence.

Permissions and troubleshooting

Check that you have the necessary permissions to use the audio devices. vi (a command-line text editor) 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

Next you need to check the permissions of the devices themselves:

   $ ls -l /dev/dsp* /dev/mixer* /dev/cdrom*

This should give you some output that looks like this:

 lrwxrwxrwx  1 root cdrom      9 2004-08-04 17:47 /dev/cdrom -> /dev/scd0
 lrwxrwxrwx  1 root cdrom      8 2004-08-02 22:16 /dev/cdrom1 -> /dev/hdc
 lrwxrwxrwx  1 root audio      9 2004-08-02 22:34 /dev/dsp -> /dev/dsp0
 crw-rw----  1 root audio 14,  3 2004-08-02 22:34 /dev/dsp0
 crw-rw----  1 root audio 14, 19 2004-08-02 22:34 /dev/dsp1
 crw-rw----  1 root audio 14, 35 2004-08-02 22:34 /dev/dsp2
 crw-rw----  1 root audio 14, 51 2004-08-02 22:34 /dev/dsp3
 lrwxrwxrwx  1 root audio     11 2004-08-02 22:34 /dev/mixer -> /dev/mixer0
 crw-rw----  1 root audio 14,  0 2004-08-02 22:34 /dev/mixer0
 crw-rw----  1 root audio 14, 16 2004-08-02 22:34 /dev/mixer1
 crw-rw----  1 root audio 14, 32 2004-08-02 22:34 /dev/mixer2
 crw-rw----  1 root audio 14, 48 2004-08-02 22:34 /dev/mixer3

If it doesn't then you may need to perform these moves:

   # chgrp audio /dev/dsp* /dev/mixer*
   # chgrp cdrom /dev/cdrom*

In this example /dev/cdrom points to the CD Burner, which is a SCSI device. If these links don't point to where you want, then you can change them like this:

   # rm /dev/cdrom ln -s /dev/hdc /dev/cdrom

check the settings in:

   # cat /etc/fstab

to check that all your devices are mounted where they should be. If you make changes to this file then you'll need to:

   # mount -a

afterwards.

In order to get alsa to function properly you may need to add some options to /etc/modutils/sound, then:

   # update-modules

You will probably need to restart ALSA before the changes take effect:

   # /etc/init.d/alsa restart

It is also worth making a configuration file in your home directory.

   $ vi ~/.asoundrc

notice that last command is in your home directory (denoted by the shell shorthand tilde) so you don't need to be root--so you shouldn't be ;-).

   # exit

will take you back to the normal prompt. See the ALSA website for further details on what to put in these files.

There is a really useful script available at http://alsa.opensrc.org/?aadebug that you can use to check that everything is set up right and to provide some useful info to accompany any further questions. You will need a little knowledge of how BASH scripts work to use this. The script is now included with the distribution.

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 and back in before these changes take effect.

MIDI

Apparently there is a bug that prevents the snd_seq module from being loaded. it can be loaded by hand like this:

 # modprobe snd_mpu401
or
 # modprobe snd_mpu401_uart

You should then see both midi input and output connections, labeled "MPU_401" in the 'Connect' panel of qjackctl, you can then set your connections to other software.

You will have to add the name of this module to the end of the file /etc/modules so it loads every time you restart your system (just add snd_mpu401 at the end).

You should also check that the module snd_seq is loaded (check that with $ lsmod in a console). If not you will have to add it to the /etc/modules list too.

You may also need to provide an options line in /etc/modutils/sound if the system fails to find the MIDI port on its own.

Xruns - Overruns

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

You can test your hard-disk performance with:

   # 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 and stop essential services, usually when you boot up and shut down. Each of these links starts with S## (an S followed by two numerical digits), change the non-essential services to K## using your favorite runlevel editor (again, plenty of choice). Likely candidates for removal are anacron, klogd and cron, most are nonessential 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.

Minimum System Requirements

You will need at least a Pentium II or equivalent.

*Basic use >= 400MHz system with 128MB of memory.
*Audio recording + minimal audio plugins >= 800MHz system with 256MB of memory.
*Soft synths ++ >= 1.0GHz system with 512 MB of memory.

If you have less resources than this, try using an external MIDI device or a SoundBlaster? type card that supports soundfonts. A good video card is also reckoned to be an advantage.

Athlons are prefered to Intel CPUs by some authors. For maximum performance, a dual CPU system is a great choice. Some problems are known with VIA and SiS chipsets.

See: http://ardour.org/requirements.php for more useful info.

There's Just One Other Thing ...

Q: What the-- I've got unresolved symbols!?

   depmod:*** unresolved symbols in /lib/modules/2.4.27-1-multimedia-686/
      kernel/drivers/media/radio/micropcm20.o
   depmod:*** unresolved symbols in /lib/modules/2.4.27-1-multimedia-686/
      alsa/sndpdaudiocf.o
   depmod:*** unresolved symbols in /lib/modules/2.4.27-1-multimedia-686/
      alsa/snd-vx-cs.o
   depmod:*** unresolved symbols in /lib/modules/2.4.27-1-multimedia-686/
      alsa/snd-440.o
   depmod:*** unresolved symbols in /lib/modules/2.4.27-1-multimedia-686/
      alsa/snd-vxpocket.o

A: Yeah, we know. You can safely ignore all these messages. The last four are because you haven't installed pcmcia-modules.

Q: Er, I have some nasty looking errors relating to shpchp?

A: Try adding it to /etc/hotplug/blacklist.

Q: I think I forgot to configure something else.

A: If you're worried you've missed something,

   # dpkg-reconfigure -a

will take you through the configurations of all packages. This will take some time and concentration.

Q: Why don't you base DeMuDi on Ubuntu?

A: Short answer: because then it would be UbMuDi. See the front page for explanation of how DeMuDi is a Custom Debian Distribution. While UbMuDi is a wonderful idea, that has long been supported by some of the DeMuDi elders, the reality is that Dapper is likley to release with out-of-the-box multimedia support, which would render a custom Ubuntu Distro unnecessary. Because both DeMuDi and Ubuntu cycle their improvements back into the central Debian repositories there is already a strong relationship between the two. Although it isn't fully tested and supported this end, people have reported success using DeMuDi packages with Ubuntu.

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. Take the following steps--

become root
read InstallApt and edit your /etc/apt/sources.list accordingly, choosing either the stable branch or the development one
from the command line issue:

   # apt-get update
   # apt-get install demudi

install the tasks you are interested in. To select them run:

   # tasksel

install the appropriate kernel for your processor:

   # apt-get kernel-image-2.6.12-3-multimedia-<Type>

where <Type> might be 386, 586tsc, 686, k6, k7.

Q: Can I upgrade my existing 1.0/1.1.0 installation?

A: Yes, using apt.

See http://lurker.agnula.org/message/20040616.113908.06d6aea7.html for 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 purposes.

Q: Is this a LiveCD?

A: No. It requires installation to your hard drive.

Q: what URL do I need to add to "/etc/apt/sources.list" in order to get ... [package]?

A: http://www.apt-get.org is as a place for people to share useful APT (Advanced Package Tool) sources for the Debian operating system. If you want to install packages not included in the standard DeMuDi or Debian repositories, look here first.

For example, to apt-get JAVA packages include these entries:

 deb http://www.tux.org/pub/java/debian testing non-free
 deb http://www.linex.org/sources/linex/debian sarge linex
 deb http://debian.jones.dk sarge misc
 deb http://debian.jones.dk sid misc

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 and click GUI, synaptic is very useable.

See InstallApt on how to edit your /etc/apt/sources.list.

Now that apt is configured, let's get all the updated packages:

   # apt-get dist-upgrade

And beyond ...

After Installation and Configuration -- Using Audio and MIDI Applications

You'll doubtless be wanting to try out some of the wonderful Linux Audio applications. Here are some good links:

Dave Phillips's excellent Tutorials.
Djcj Quick Toots
Ish's HOWTO about using alsa, jack, ardour and jamin together to record and master digital audio.
Emmanuel Saracco's HOWTO create music with GNU/Linux.

Additional Notes

If by some strange chance you find a bug ;-) first check the existing tickets by clicking on the View Tickets link (there's one at the top of every page. If the problem is not reported there it is worth mailing the list to see if anyone else is having the same problem. If you want to create a new report, just click on the New Ticket link and fill in the boxes.

If you want to discuss this FAQ or write a HOW-TO yourself or make a contribution, please subscribe to the mailing lists and let us know what you think. Most of the business of A/DeMuDi goes through this list, it's a very helpful and user friendly community. Never be afraid to ask awkward questions!

Other previously answered questions are available at the mailing list archives. Yes, this is a hint. ;)

Make some great music!

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