LIGS -- Debian Issue 15

#### "Linux Gazette...making Linux just a little more fun!"

SSC is expanding Matt Welsh's Linux Installation & Getting Started by adding chapters about each of the major distributions. Each chapter is being written by a different author in the Linux community. Here's a sneak preview -- the Debian chapter by Boris Beletsky, one of the Debian developers. --Editor

## Debian Linux Installation & Getting Started

#### By Boris D. Beletsky, borik@isracom.co.il

Table of contents

1. Getting and installing Debian GNU/Linux.
  1.1 Getting floppy images.
  1.2 Preparing the floppies.
  1.3 Downloading the packages.
  1.4 Booting from floppies and installing Debian GNU/Linux.
2. Running Debian GNU/Linux.
  2.1 Debian packaging system and package installation utilities.
    2.1.1 Package Classifications.
    2.1.2 Package Relationships.
    2.1.3 Dselect.
    2.1.4 Dpkg.
3. About Debian.
  3.1 Debian community.
  3.2 Mailing lists.
  3.3 Bug tracing system.
4. Almost the end.
  4.1 Acknowledgments.
  4.2 Last Note.

## 1. Getting and installing Debian GNU/Linux

META: I will not expand on system requirements here because this subject is surely covered in previous chapters of this book or in the "Linux Hardware Compatibility HOWTO" located at http://sunsite.unc.edu/mdw/HOWTO/Hardware-HOWTO.html.

1.1 Getting floppy images

If you have access to the Internet, the best way to get Debian is via anonymous FTP (File Transfer Protocol). The home ftp site of Debian is located at ftp.debian.org in /pub/debian directory. The structure of debian archive is built as following:

> ./stable/ | (latest stable debian release)
> ./stable/binary-i386 | (debian packages for i386 architecture)
> ./stable/disks-i386 | (boot and root disks needed for Debian installation)
> ./stable/disks-i386/current | (The current boot floppy set)
> ./stable/disks-i386/special-kernels | (Special kernels and boot floppy disks, for hardware configurations that refuse working with our regular boot floppies)
> ./stable/msdos-i386 | (dos short file names for debian packages)

For base installation of Debian you will need about 12 megabytes of disk space, and some floppies. First you will need boot and root floppy images. Debian provides two sets of installation floppy images, for floppy 1440 and 1200 floppy drives. Check what floppy drive your system boots from, (it is the A: drive under Dos) and download the appropriate disk set. Files in ./stable/disks-i386/current:

> Filename | Label | Description
> rsc1440.bin | "Rescue Floppy" | Floppy set for systems with 1.44MB floppy drive and at least 5MB RAM.
> drv1440.bin | "Device Drivers"
> base14-1.bin | "Base 1"
> base14-2.bin | "Base 2"
> base14-3.bin | "Base 3"
> base14-4.bin | "Base 4"
> root.bin | "Root Disk"
> rsc1440r.bin | "Rescue Floppy" | Optional Rescue Disk image for low memory systems (less then 5MB of RAM)
> rsc1200r.bin | "Rescue Floppy" | Floppy set for systems with 1.2MB floppy drive
> drv1200.bin | "Device Drivers"
> base12-1.bin | "Base 1"
> base12-2.bin | "Base 2"
> base12-3.bin | "Base 3"
> base12-4.bin | "Base 4"
> root.bin | "Root Disk"

Choose the appropriate floppy set, corresponding to your hardware setup (Ram and floppy drive). What ever you choose, at the end you have to have 7 floppy images which contain, "Rescue Floppy", "Device Drivers, "Base 1", "Base 2" ..., "Root Disk". (Note, "Root Disk" image is the same for all drives and system types.)

1.2 Preparing the floppies

Next step is to prepare the floppies for the installation by copying the images into disks. Hence those files are disk images, they should be copied block-by-block. In Dos you can use the RAWRITE utility for that purpose located at ftp://ftp.debian.org/pub/debian/tools/rawrite2.exe. Here is a brief explanation on how to use it:

    C:\> RAWRITE2 <file> <drive>

By executing the `RAWRITE2` command as stated above, you will accomplish the following, the file "<file>" will be copied block-by-block into the drive "<drive>".

On any Unix like operation systems you can use `dd(1)`:

    # dd if=file of=/dev/fd0 bs=10k

META: In some Unix systems the first floppy device maybe named differently.

When you finish rawriting don't forget to mark the floppies else you will get confused later.

1.3 Downloading the packages

In order to install and use Debian you will need more then the base system. To decide what packages you want on your system download the file 'Packages' from ftp://ftp.debian.org/pub/debian/stable/Packages. This file is a list of Debian packages available for the moment in stable Debian distribution. This file comes in special format, evry package has it's own entry separated by a blank line, here is an explanation of each field in the package entry:

> Package: | The name of the package.
> Priority: | The state of importance of the package.
> Required - | Should be installed for system to work properly.
> Important - | Not required though, important.
> Optional - | Doesn't have to be installed but still useful.
> Extra - | Package may conflict with. other packages with higher priorities.
> Section: | This field declares a Debian section of the package.
> Base - | base system.
> Devel - | development tools.
> X11 - | XWindows packages.
> Admin - | administration utilities.
> Doc - | documentation.
> Comm - | various communication utilities.
> Editors - | various editors.
> Electronics - | electronics utilities.
> Games - | games (you knew that didn't you?).
> Graphics - | graphics utilities.
> Hamradio - | utilities for internet radio.
> Mail - | email clients and servers.
> Math - | mathematics utilities (such as calculators, etc...).
> Net - | various tools to connect to the network (usualy TCP/IP).
> News - | servers and clients for internet news (NNTP).
> Shells - | shells, such as tcsh, bash.
> Sound - | any sound applications (such as, cd players).
> TeX - | anything that can read, write, and convert TeX.
> Text - | applications to manipulate texts. (such as nroff)
> Misc - | everything else that doesn't fit in the above.
> Maintainer: | The name of the person who maintains the package and his contact Email address.
> Version: | The version of the package in the following format: <upstream-version>-<debian-version>.
> Depends: | That field declares the dependency of the package with another one (or more), that means that this package can not be used or installed without the other packages listed in this field.
> Recommends: | Another level of package dependencies. It is strongly recommended to install the packages listed in this field together with the package this entry entry describes.
> Suggests: | Packages listed in this field maybe useful to the packages this entry entry describes.
> Filename: | Filename of the package on ftp/cdrom.
> Msdos-Filename: | Filename of the package in dos short format.
> Size: | The size of the package after the installation.
> Md5sum: | The md5sum check to be sure that this package came from us.
> Description: | This field will tell you about the package (finally!), DO NOT download the package without reading it.

META: More detailed explanation on Debian packaging scheme you can find in section 2.1 of this chapter.

The above should give you an idea on how to build your personal download list. When you have the list of packages you want to download, you will have to decide how and when you want to download them. If you are an experienced user you may want to download the netbase package, and slip/ppp if needed, for later downloading from linux. Otherwise you can download all the packages from your current OS and install them later from mounted partition.

1.4 Booting from floppies and installing Debian GNU/Linux

The Rescue Floppy

  Place the Rescue floppy in the a: floppy drive, and reset the system by pressing reset, turning the system off and then on, or by pressing Control-Alt-Del on the keyboard. The floppy disk should be accessed, and you should then see a screen that introduces the rescue floppy and ends with the boot: prompt. It's called the Rescue floppy because you can use it to boot your system and perform repairs if there is ever a problem that makes your hard disk unbootable. Thus, you should save this floppy after you've installed your system.

  You can do two things at the boot: prompt. You can press the function keys F1 through F10 to view a few pages of helpful information, or you can boot the system. If you have any hardware devices that aren't made accessible from Linux correctly when Linux boots, you may find a parameter to add to the boot command line in the screens you see by pressing F3, F4, and F5. If you add any parameters to the boot command line, be sure to type the word linux and a space before the first parameter. If you simply press Enter, that's the same as typing linux without any special parameters.

  If this is the first time you're booting the system, just press Enter and see if it works correctly. It probably will. If not, you can reboot later and look for any special parameters that inform the system about your hardware.

  Once you press Enter, you should see the message Loading..., and then Uncompressing Linux..., and then a page or so of cryptic information about the hardware in your system. There may be a many messages in the form can't find something, or something not present, can't initialize something, or even this driver release depends on something. Most of these messages are harmless. You see them because the installation boot disk is built to run on computers with many different peripheral devices. Obviously, no one computer will have every possible peripheral device, so the operating system may emit a few complaints while it looks for peripherals you don't own. You may also see the system pause for a while. This happens when it is waiting for a device to respond, and that device is not present on your system. If you find the time it takes to boot the system unacceptably long, you can create a custom kernel once you've installed your system without all of the drivers for non-existent devices.

Low-Memory Systems

  If you system has 4MB RAM, you may now see a paragraph about low memory and a text menu with three choices. If your system has enough RAM you won't see this at all, and you'll go directly to the color-or-monochrome dialog box. If you get the low-memory menu, you should go through its selections in order. Partition your disk, activate the swap partition, and start the graphical installation system. The program that is used to partition your disk is called cfdisk, and you should use the manual page for cfdisk as an aid in its operation. Use cfdisk to create a Linux Swap partition (type 82). You need the swap partition to provide virtual memory during the installation process, since that process will use more memory than you have in your system. Select the size for the amount of virtual memory you intend to use once your system is installed. 16 megabytes is probably the lowest amount that's practical, use 32 megabytes if you can spare the space, and 64 if your disk is large enough that you won't miss that much.

The Color-or-Monochrome Dialog Box

  Once the system has finished booting, you should see the color or monochrome choice dialog box. If your monitor displays black-and-white, press Enter to continue with the installation. Otherwise, use the arrow key to move the cursor to the Color menu item and then press Enter. The display should change from black-and-white to color. Then press Enter again to continue with the installation.

The Main Menu

  You may see a dialog box that says The installation program is determining the current state of your system. On some systems, this will go by too quickly to read. You'll see this dialog box between steps in the main menu. The installation program will check the state of the system in between each step. This checking allows you to re-start the installation without losing the work you have already done if you happen to halt your system in the middle of the installation process. If you have to restart an installation, you will have to configure color-or-monochrome, configure your keyboard, re-activate your swap partition, and re-mount any disks that have been initialized. Anything else that you have done with the installation system will be saved.

  During the entire installation process, you will be presented with the main menu. The choices at the top of the menu will change to indicate your progress in installing the system. Phil Hughes wrote in Linux Journal that you could teach a chicken to install Debian! He meant that the installation process was mostly just pecking at the return key. The first choice on the installation menu is the next action that you should perform according to what the system detects you have already done. It should say Next, and at this point the next item should be Configure the Keyboard.

Configuring the Keyboard

  Make sure the highlight is on the Next item, and Press Enter to go to the keyboard configuration menu. Select a keyboard that conforms to the layout used for your national language, or select something close if the keyboard layout you want isn't represented. Once the system is installed, you'll be able to select a keyboard layout from a wider range of choices. Move the highlight to the keyboard selection you desire and press enter. Use the arrow keys to move the highlight - they are in the same place in all national language keyboard layouts, so they are independent of the keyboard configuration.

The Shell

  If you are an experienced Unix or Linux user, press LeftAlt-F2 to get to the second virtual console. That's the Alt key on the left-hand side of the space bar, and the F2 function key, at the same time. This is a separate window running a Bourne shell clone called ash. At this point you are booted from the RAM disk, and there is a limited set of Unix utilities available for your use. You can see what programs are available with the command ls /bin /sbin /usr/bin /usr/sbin. Use the menus to perform any task that they are able to do - the shell and commands are only there in case something goes wrong. In particular, you should always use the menus, not the shell, to activate your swap partition, because the menu software can't detect that you've done this from the shell. Press LeftAlt-F1 to get back to menus. Linux provides up to 64 virtual consoles, although the Rescue floppy only uses a few of them.

Last Chance!

  Did we tell you to back up your disks? Here's your first chance to wipe out all of the data on your disks, and your last chance to save your old system. If you haven't backed up all of your disks, remove the floppy from the drive, reset the system, and run backups.

Partition Your Hard Disks

  If you have not already partitioned your disks for Linux native and Linux swap filesystems, the menu item Next will be Partition a Hard Disk. If you have already created at least one Linux Native and one Linux Swap disk partition, the Next menu selection will be Initialize and Activate the Swap Disk Partition, or you may even skip that step if your system had low memory and you were asked to activate the swap partition as soon as the system started. Whatever the Next menu selection is, you can use the down-arrow key to select Partition a Hard Disk.

  The Partition a Hard Disk menu item presents you with a list of disk drives you can partition, and runs the cfdisk program, which allows you to create and edit disk partitions. The cfdisk manual page is included with this document, and you should read it now. You must create one "Linux" (type 83) disk partition, and one "Linux Swap" (type 82) partition.

  Your swap partition will be used to provide virtual memory for the system and should be between 16 and 128 megabytes in size, depending on how much disk space you have and how many large programs you want to run. Linux will not use more than 128 megabytes of swap, so there's no reason to make your swap partition larger than that. a swap partition is strongly recommended, but you can do without one if you insist, and if your system has more than 16 megabytes of RAM. If you wish to do this, please select the Do Without a Swap Partition item from the menu.

  The "Linux" disk partition will hold all of your files, and you may make it any size between 40 megabytes and the maximum size of your disk minus the size of the swap partition. If you are already familiar with Unix or Linux, you may want to make additional partitions - for example, you can make partitions that will hold the /var, and /usr, filesystems.

Initialize and Activate the Swap Disk Partition

  This will be the Next menu item once you have created one disk partition. You have the choice of initializing and activating a new swap partition, activating a previously-initialized one, and doing without a swap partition. It's always permissible to re-initialize a swap partition, so select Initialize and Activate the Swap Disk Partition unless you are sure you know what you are doing. This menu choice will give you the option to scan the entire partition for un-readable disk blocks caused by defects on the surface of the hard disk platters. This is useful if you have MFM, RLL, or older SCSI disks, and never hurts. Properly-working IDE disks don't need this choice, as they have their own internal mechanism for mapping out bad disk blocks.

  The swap partition provides virtual memory to supplement the RAM memory that you've installed in your system. It's even used for virtual memory while the system is being installed. That's why we initialize it first.

Initialize a Linux Disk Partition

  At this point, the Next menu item should be Initialize a Linux Disk Partition. If it isn't, it's because you haven't completed the disk partitioning process, or you haven't made one of the menu choices dealing with your swap partition.

  You can initialize a Linux Disk partition, or alternately you can mount a previously-initialized one.

  These floppies will not upgrade an old system without removing the files - Debian provides a different procedure than using the boot floppies for upgrading existing Debian systems. Thus, if you are using old disk partitions that are not empty, you should initialize them (which erases all files) here. You must initialize any partitions that you created in the disk partitioning step. About the only reason to mount a partition without initializing it at this point would be to mount a partition upon which you have already performed some part of the installation process using this same set of installation floppies.

  Select the Next menu item to initialize and mount the / disk partition. The first partition that you mount or initialize will be the one mounted as / (pronounced root). You will be offered the choice to scan the disk partition for bad blocks, as you were when you initialized the swap partition. It never hurts to scan for bad blocks, but it could take 10 minutes or more to do so if you have a large disk.

  Once you've mounted the / partition, the Next menu item will be Install the Base System unless you've already performed some of the installation steps. You can use the arrow keys to select the menu items to initialize and/or mount disk partitions if you have any more partitions to set up. If you have created separate partitions for /var, /usr, or other filesystems, you should initialize and/or mount them now.

Install the Base System

  This should be the Next menu step after you've mounted your / disk, unless you've already performed some of the installation steps on /. Select the Install the Base System menu item. There will be a pause while the system looks for a "local copy" of the base system. This search is for CD-ROM installations and will not succeed, and you'll be offered a menu of drives to use to read the base floppies. Select the appropriate drive. Feed in the Base 1, 2, and 3 (and 4 if you are using 1.2MB floppies) as requested by the program. If one of the base floppies is unreadable, you'll have to create a replacement floppy and feed all 3 (or 4) floppies into the system again. Once the floppies have all been read, the system will install the files it's read from them. This could take 10 minutes or more on slow systems, less on faster ones.

Install the Operating System Kernel

  At this point, the Next menu item should be Install the Operating System Kernel. Select it, and you will be prompted to select a floppy drive and insert the rescue floppy. This will copy the kernel on to the hard disk. In a later step this kernel will be used to create a custom boot floppy for your system, and to make the hard disk bootable without a floppy.

Install the Device Drivers

  Select the menu item to install the device drivers, and you'll be prompted to insert the device drivers floppy. The device drivers will be copied to your hard disk. Select the Configure Device Drivers menu item and look for devices that are on your system. Configure those device drivers, and they will be loaded whenever your system boots.

  There is a menu selection for PCMCIA device drivers, but you need not use it . Once your system is installed, you can install the pcmcia-cs package. This detects PCMCIA cards automatically, and configures the ones it finds. It also copes with hot-plugging the cards while the system is booted - they will all be configured as they are plugged in, and de-configured when you unplug them.

Configure the Base System

  At this point you've read in all of the files that make up a minimal Debian system, but you must perform some configuration before the system will run. Select the Configure the Base System menu item.

  You'll be asked to select your time zone. Look for your time zone or region of the world in the menu, and type it at the prompt. This may lead to another menu, in which you can select your actual time zone.

  Next, you'll be asked if your system clock is to be set to GMT or local time. Select GMT if you will only be running Linux and Unix on your system, and select local time if you will be running another operating system such as DOS or Windows. Unix and Linux keep GMT time on the system clock and use software to convert it to the local time zone. This allows them to keep track of daylight savings time and leap years, and even allows users who are logged in from other time zones to individually set the time zone used on their terminal. If you run the system clock on GMT and your locality uses daylight savings time, you'll find that the system adjusts for daylight savings time properly on the days that it starts and ends.

Configure the Network

  You'll have to configure the network even if you don't have a network, but you'll only have to answer the first two questions - what is the name of your computer?, and is your system connected to a network?.

  If you are connected to a network, here come some questions that you may not be able to figure out on your own - check with your system administrator if you don't know:

  - Your host name.
  - Your domain name.
  - Your computer's IP address.
  - The netmask to use with your network.
  - The IP address of your network.
  - The broadcast address to use on your network.
  - The IP address of the default gateway system you should route to, if your network has a gateway.
  - The system on your network that you should use as a DNS (Domain Name Service) server.
  - Whether you connect to the network using Ethernet.

  Some technical details you might, or might not, find handy: the program will guess that the network IP address is the bitwise-AND of your system's IP address and your netmask. It will guess the broadcast address is the bitwise OR of your system's IP address with the bitwise negation of the netmask. It will guess that your gateway system is also your DNS server. If you can't find any of these answers, use the system's guesses - you can change them once the system has been installed, if necessary, by editing /etc/init.d/network .

Make the Hard Disk Bootable

  If you select to make the hard disk boot directly to Linux, you will be asked to install a master boot record. If you aren't using a boot manager (and this is probably the case if you don't know what a boot manager is), answer yes to this question. The next question will be whether you want to boot Linux automatically from the hard disk when you turn on your system. This sets Linux to be the bootable partition - the one that will be loaded from the hard disk. If you answer no to this question, you can set the bootable partition later using the DOS fdisk program, or with the Linux fdisk or activate programs.

  If you are installing Linux on a drive other than the first hard disk in your system, be sure to make a boot floppy. The boot ROM of most systems is only capable of directly booting from the first hard drive, not the second one. You can, however, work around this problem once you've installed your system. To do so, read the instructions in the directory /usr/doc/lilo.

Make a Boot Floppy

  You should make a boot floppy even if you intend to boot the system from the hard disk. The reason for this is that it's possible for the hard disk bootstrap to be mis-installed, but a boot floppy will almost always work. Select Make a Boot Floppy from the menu and feed the system a blank floppy as directed. Make sure the floppy isn't write-protected, as the software will format and write it. Mark this the "Custom Boot" floppy and write-protect it once it has been written.

The Moment of Truth

  This is what electrical engineers call the smoke test - what happens when you turn on a new system for the first time. Remove the floppy disk from the floppy drive, and select the Reboot the System menu item. If the Linux system doesn't start up, insert the Custom Boot floppy you created and reset your system. Linux should boot. You should see the same messages as when you first booted the installation boot floppy, followed by some new messages.

Set the Root Password

  This is the password for the super-user, a login that bypasses all security protection on your system. It should only be used to perform system administration, and only for as short a time as possible. Do not use root as your personal login. You will be prompted to create a personal login as well, and that's the one you should use to send and receive e-mail and perform most of your work, not root. The reason to avoid using root's privileges is that you might be tricked into running a trojan-horse program - that is a program that takes advantage of your super-user power to compromise the security of your system behind your back. Any good book on Unix system administration will cover this topic in more detail - consider reading one if it's new to you. The good news is that Linux is probably more secure than other operating systems you might run on your PC. DOS and Windows, for example, give all programs super-user privilege. That's one reason that they have been so plagued by viruses.

  All of the passwords you create should contain from 6 to 8 characters, and should contain both upper and lower-case characters, as well as punctuation characters.

  Once you've added both logins, you'll be dropped into the dselect program. The Dselect Tutorial is required reading before you run dselect. Dselect allows you to select packages to be installed on your system. If you have a CD-ROM or hard disk containing the additional Debian packages that you want to install on your system, or you are connected to the Internet, this will be useful to you right away. Otherwise, you may want to quit dselect and start it later, once you have transported the Debian package files to your system. You must be the super-user (root) when you run dselect. If you are about to install the X Window system and you do not use a US keyboard, you should read the X11 Release note for non-US-keyboard users.

Log In

  After you've quit dselect, you'll be presented with the login prompt. Log in using the personal login and password you selected. Your system is now ready to use.

## 2. Running Debian GNU/Linux.

This section will deal Debian packaging system and debian specific utilities. Ab ovo.

2.1 Debian packaging system and package installation utilities

Debian distributions comes in archives called packages. Every package is a collection of files (software, usually) that can be installed using "dpkg" or "dselect". In addition the package contains some information about it self that is read by the installation utilities.

2.1.1 Package Classifications

The packages included with Debian GNU/Linux are classified according to how essential they are (priority), and according to their functionality (section).

The "priority" of a package indicates how essential or necessary it is. We have classified all packages into four different priority levels:

Required

  "Required" packages are packages that must be installed for the system to correctly operate. The required packages are the packages that were installed with the base system. Thus, they are already installed. Never, never, never remove a required package from the system unless you are absolutely sure what you are doing. This bears repeating. Never, never, never remove a required package from the system unless you are absolutely sure what you are doing. It is likely that doing so will render your system completely unusable.

  Required packages are abbreviated in dselect as "Req".

Important

  "Important" packages are packages that are found on almost all Unix-like operating systems. Such packages include cron', man', and vi'.

  Important packages are abbreviated in dselect as "Imp".

Standard

  "Standard" packages are packages that, more or less, comprise what we consider to be the "standard", character-based Debian GNU/Linux system. The Standard system includes a fairly complete software development environment and GNU Emacs.

  Standard packages are abbreviated in dselect as "Std".

Optional

  "Optional" packages are packages that comprise a fairly complete system. The Optional system includes a fairly complete TeX environment and the X Window System.

  Optional packages are abbreviated in dselect as "Opt".

Extra

  "Extra" packages are packages that are only useful to a small or select group of people, or that would be installed for a specific purpose rather than as a general part of an operating system. Such packages include electronics and ham radio packages.

  Extra packages are abbreviated in dselect as "Xtr".

By default, dselect automatically selects the Standard system, if the user doesn't want to individually select the packages to be installed.

The "section" of a package indicates the functionality or use of a package. Packages on the CD-ROM and in FTP archive are arranged according to section. The section names are fairly self-explanatory: for example, the category admin' contains packages for system administration, and the category devel' contains packages for software development and programming. Unlike priority levels, there are many sections, and more will probably be added in the future, so we do not individually describe any of them in the manual.

2.1.2 Package Relationships

Each package includes information about how it relates to the other packages included with the system. There are four package relationships in Debian GNU/Linux: conflicts, dependencies, recommendations, and suggestions.

A "conflict" occurs when two or more packages cannot be installed on the same system at the same time. A good example of conflicting packages are mail transfer agents (MTAs). A mail transfer agent is a program that delivers electronic mail to other users on the system or to other machines on the network. Debian GNU/Linux includes two alternative mail transfer agents: sendmail' and smail'.

Only one mail transfer agent can be installed on the system at a time, as they both do the same job and are not designed to coexist. Therefore, the sendmail' and smail' packages conflict. If you try to install sendmail' when smail' is already installed, the package maintenance system will refuse to install it. Likewise, if you try to install smail' when sendmail' is already installed, it will refuse to install it.

A "dependency" occurs when one package requires another package to function properly. Continuing our electronic mail example, users read mail with programs called mail user agents (MUAs). Popular mail user agents include elm', pine', and Emacs RMAIL. It is normal to install several MUAs at once, so these packages do not conflict. But a mail user agent does not deliver mail--it uses the mail transfer agent to do that. Therefore, all mail user agent packages depend on a mail transfer agent.

A package can also "recommend" or "suggest" other related packages.

2.1.3 Dselect

META: This section provides brief tutorial on Debian Dselect, for more detailed explanation please refer to Dselect Manual located at ftp://ftp.debian.org/debian/Debian-1.2/disks-i386/current/dselect.beginner.6.html

Dselect is simple menu driven interface that will help you install packages. It is used to select packages you wish to install.

It will step you through the package installation process as follows:

- Choose the access method to use.
- Update list of available packages, if possible.
- Request which packages you want on your system.
- Install and upgrade wanted packages.
- Configure any packages that are unconfigured.
- Remove unwanted software.

The main dselect screen looks like that:

    ------------------------------------------------------------------

    Debian Linux `dselect' package handling front end.
       0. [A]ccess      Choose the access method to use.
       1. [U]pdate      Update list of available packages, if possible.
       2. [S]elect      Request which packages you want on your system.
       3. [I]nstall     Install and upgrade wanted packages.
       4. [C]onfig      Configure any packages that are unconfigured.
       5. [R]emove      Remove unwanted software.
       6. [Q]uit        Quit dselect.

    ------------------------------------------------------------------

META: There are two ways of selecting the option from the menu, one is choosing it with arrows, another one is pressing the key in []'s.

Access

  In this menu you can choose the method you will use for obtaining/installing the packages.

  Abbrev. | Description
  cdrom | Install from a CD-ROM.
  nfs | Install from an NFS server (not yet mounted).
  harddisk | Install from a hard disk partition (not yet mounted).
  mounted | Install from a filesystem which is already mounted.
  floppy | Install from a pile of floppy disks.
  ftp | Install using ftp.

Update

  Dselect will read the packages list file (exactly the same file that was discussed in the 1.3 section) and will create a database of available packages locally on your system.

Select

This is where you select the packages, choose your love and hit <Enter>. If you have a slow machine be aware that the screen will clear and can remain blank for 15 seconds so don't start bashing keys at this point. The first thing that comes up on the screen is page 1 of the Help file. You can get to this help by hitting ? at any point in the Select screens and you can page through the help screens by hitting the . (full stop) key.

To exit the Select screen after all selections are complete, hit <Enter>. This will return you to the main screen _if_ there are no problems with your selection. Else you will be asked to deal with those problems. When you are happy with any given screen hit <Enter> to get out.

Problems are quite normal and are to be expected. If you select package A and that package requires package B to run, then dselect will warn you of the problem and will most likely suggest a solution. If package A conflicts with package B (they are mutually exclusive) you will be asked to decide between them.

Install

  Dselect runs through the entire 800 packages and installs those selected. Expect to get asked to make decisions as you go. It is often useful to switch to a different shell to compare, say, an old config with a new one. If the old file is conf.modules the new one will be conf.modules.dpkg-new.

  The screen scrolls past fairly quickly on a new machine. You can stop/start it with ^S/^Q and at the end of the run you will get a list of any uninstalled packages. If you want to keep a record of everything that happens use normal Unix features like tee or script.

Configure

  Most packages get configured in step 3, but anything left hanging can be configured here.

Remove

  Remove packages that no longer needed.

Quit

  Au revoir.

2.1.4 Dpkg

META: This section provides a brief tutorial on Debian Dpkg program.

Dpkg is command line tool for installing and manipulating debian packages. It has several switches, which allow you to install, configure, update, remove and do other operations on debian packages (even build your own). Dpkg also allowd you to list the available packages, list files 'owned' by packages, find which package the file is owned by, et cetera.

Installing new packages / updating existing ones.

  It's as simple as any other dpkg operation. All you have to do is to type the following command:

      # dpkg -i <filename.deb>

  where <filename> is the name of the file containing a debian package, such as, 'tcsh_6.06-11_i386.deb'. Dpkg is partly interactive; during the installation it may ask you additional questions, such as, wether to install the new version of a configuration file, or to keep the old one.

  You may also unpack a package without configuring it: type:

      dpkg --unpack <filename>

  If the package you are trying to install depends on a non-existing package or on a newer version of a package you have, or if any other problem occurs during the installation, dpkg will abort with a verbose error message.

Configure installed packages

  It happens that dpkg aborts during an installation and leaves the package installed, though unconfigured. It also happens that the users unpack packages without configuring it. Debian packaging system requires the package to be configured to avoid dependency problems. More than that, some packages require configuration to work properly.

  To configure it, simply type:

      dpkg --configure <package>

  where <package> is the name of the package, such as, 'tcsh' (which is not the same thing as a filename we mentioned above).

Removing installed packages

  In Debian package system, there are two ways to murder a package, called 'remove' and 'purge'. The 'remove' switch just removes the specified package; the 'purge' switch also purges the configuration files. The usage is:

      dpkg -r <package>
      dpkg --purge <package>

  Of course, if there are any installed packages that depend on the one you wish to remove, the package will not be removed, and dpkg will abort with a verbose error message.

Reporting package status

  To report the status of the package (i.e., installed, not installed, unconfigured, etc.), type:

      dpkg -s <package>

Listing available packages

  To list the installed packages that match some pattern, type:

      dpkg -l [<package-name-pattern>]

  where <package-name-pattern> is an optional argument specifying a pattern for the package names to match, such as, "*sh". Yes, normal shell wildcards are allowed. If you don't specify the pattern, all the installed packages will be listed.

Listing files 'owned' by package

  To list all the files owned by a particular package, simply type:

      dpkg -L <package>

  However, it will not list the files created by package-specific installation scripts.

Finding package 'owning' a file

  To find the package wich is 'owning' a particular file, type the following command:

      dpkg -S <filename-pattern>

  where <filename-pattern> is the pattern for the file to search for. Again, normal shell wildcards are allowed.

Summary

  Dpkg is very simple to use and is preferred over dselect when all you have to do is to install, upgrade or remove a small number of packages. It also has some functionality which dselect (which is, in fact, an interface to dpkg) doesn't have, such as, finding package 'owning' a file. Here we haven't describe all the options dpkg have. For the full list, refer to dpkg(8) man page.

## 3. About Debian

3.1 Debian community

Debian project was created by Ian Murdock in 1993, initially under the sponsorship of the Free Software Foundation's GNU project. Later, Debian has parted from FSF. Debian was created is the result of a volunteer effort to create a free, high-quality Unix-compatible operating system based on Linux kernel, complete with a suite of applications.

Debian community is a group of above 150 unpaid volunteers from over the world who collaborate via the Internet. The founders of the project have formed the organization "Software in the Public Interest" to sponsor Debian GNU/Linux development.

Software in the Public Interest

Software in the Public Interest (SPI) is a non-profit organization formed when FSF withdrew their sponsorship of Debian. The purpose of the organization is to develop and distribute free software. Its goals are very much like those of FSF, and it encourages programmers to use the GNU General Public License on their programs. However, SPI has a slightly different focus in that it is building and distributing a Linux system that diverges in many technical details from the GNU system planned by FSF. SPI still communicates with FSF, and it cooperates in sending them changes to GNU software and in asking its users to donate to FSF and the GNU project.

SPI can be reached at:

E-Mail: bruce@pixar.com Postal address:

Software in the Public Interest
P.O. Box 70152
Pt. Richmond, CA 94807-0152

Phone: 510-215-3502 (Bruce Perens at work)

3.2 Mailing lists

There are several Debian-related mailing lists:

debian-announce@lists.debian.org
  Moderated. Major system announcements. Usually about one message per month.

debian-changes@lists.debian.org
  Announcements of new package releases for the stable distribution. Usually several messages per day.

debian-devel-changes@lists.debian.org
  Announcements of new package releases for the unstable distribution. Usually several messages per day.

debian-user@lists.debian.org
  A mailing lists where users of Debian ask for and get support. Usually about 50 packages per day.

debian-sparc@lists.debian.org,
debian-alpha@lists.debian.org,
debian-68k@lists.debian.org
  Lists for those who are involved in porting Debian software to SPARC / DEC Alpha / Motorolla 680x0 platforms.

There are also several mailing lists for Debian developers.

You can subscribe to those mailing list by mail or via www, for more information please visit http://www.debian.org/

3.3 Bug tracing system.

Debian project has a bug tracing system which handles the bug reports provided by users. As soon as the bug report is received, the bug is given a number and all the information provided on this particular bug is stored in a file and mailed to the maintainer of the package. When the bug is fixed, it must be marked as done ("closed") by the maintainer; however, if it was closed by mistake, it may be reopened.

To receive more info on the bug tracing system, send e-mail to request@bugs.debian.org with "help" in the body.

## 4. Almost the end.

4.1 Acknowledgments.

Many thanks to Bruce Perens, and other authors of Debian related materials that I've used in order to write this chapter.

Thanks a lot to Vadik Vygonets, my beloved cousin, that also helped me very much.

And thanks a lot to all members of Debian community for their hard work, let's hope that Debian will become even better.

4.2 Last Note

Hence Debian changes very fast, alot of facts may change faster then the book, but this document will be updated regularly, you can find it at http://www.cs.huji.ac.il/~borik/debian/ligs/

##### Copyright © 1997, Boris D. Beletsky
Published in Issue 15 of the Linux Gazette, March 1, 1997