Debian Gnu/linux : Guide to Installation and Usage

Letter C Pressed Simultaneously). This Will Often Stop the

program.

1.4.2 Conventions

Before going on, it’s important to be familiar with the typographical conventions used in this book.

When you should simultaneously hold down multiple keys, a notation like CTRL-a will be used. This means “press the Ctrl key and press lowercase letter a.” Some keyboards have both Alt and Meta; most home computers have only Alt, but the Alt key behaves like a Meta key. So if you have no Meta key, try the Alt key instead.

Keys like Alt and Meta are called modifier keys because they change the meaning of standard keys like the letter A. Sometimes you need to hold down more than one modifier; for example, Meta-Ctrl-a means to simultaneously press Meta, Ctrl, and lowercase a.

Some keys have a special notation—for example, Ret (Return/Enter), Del (Delete or sometimes Backspace), Esc (Escape). These should be fairly self-explanatory.

Spaces used instead of hyphens mean to press the keys in sequential order. For example, CTRL-a x RET means to simultaneously type Ctrl and lowercase a, followed by the letter x, followed by pressing Return. (On some keyboards, this key is labeled Enter. Same key, different name.)

In sample sessions, bold face text denotes characters typed by the user, italicized text denotes comments about a given part of the sample session, and all other text is output from entering a command. For shorter commands, you’ll sometimes find that the command can be found within other text, highlighed with a monospace font.

2. Getting Started

“A journey of a thousand miles must begin with a single step.” —Lao-Tsu

Now that you’ve read about the ideas and philosophy behind Linux and Debian, it’s time to start putting it on your computer! We start by talking about how to prepare for a Debian install, then about partitioning your disk, and finally, how to start up the installation system.

2.1 Supported Hardware

Debian does not impose hardware requirements beyond the requirements of the Linux kernel and the GNU tools.

Rather than attempting to describe all the different hardware configurations that are supported for the PC platform, this section contains general information and pointers to where additional information can be found.

There are two excellent places to check for detailed information: the Debian System Requirements list and the Linux Documentation Project Hardware Compatibility HOWTO. For information on video card support, you may also want to look at the XFree86 Project web site.

http://www.debian.org/releases/slink/i386/ch-hardware-req.en.html

http://metalab.unc.edu/LDP/HOWTO/Hardware-HOWTO.html

http://www.xfree86.org/

2.1.1 Memory and Disk Space Requirements

You must have at least 4MB of memory and 35MB of available hard disk space. If you want to install a reasonable amount of software, including the X Window system, and some development programs and libraries, you’ll need at least 300MB. For an essentially full installation, you’ll need around 800MB. To install everything available in Debian, you’ll probably need around 2GB. Actually, installing everything doesn’t make sense because some packages provide the same services.

2.2 Before You Start

Before you start, make sure to back up every file that is now on your system. The installation procedure can wipe out all of the data on a hard disk! The programs used in installation are quite reliable and most have seen years of use; still, a false move can cost you. Even after backing up, be careful and think about your answers and actions. Two minutes of thinking can save hours of unnecessary work.

Debian makes it possible to have both Debian GNU/Linux and another operating system installed on the same system. If you plan to use this option, make sure that you have on hand the original CD-ROM or floppies of the other installed operating systems. If you repartition your boot drive, you may find that you have to reinstall your existing operating system’s boot loader or the entire operating system itself.

A boot loader is responsible starting an operating system’s boot procedure.

2.2.1 Information You Will Need

If your computer is connected to a network 24 hours a day (i.e., an Ethernet or similar LAN connection—not a PPP connection), you should ask your network’s system administrator for the following information:

◼ Your host name (you may be able to decide this on your own) ◼ Your domain name ◼ Your computer’s IP address ◼ The IP address of your network ◼ The netmask to use with 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 server ◼ Whether you connect to the network using Ethernet ◼ Whether your Ethernet interface is a PCMCIA card, and if so, the type of PCMCIA controller you have If your only network connection is a telephone line using PPP or an equivalent dialup connection, you don’t need to worry about getting your network set up until your system is already installed. See

Section 11.1 on Page 99 for Information on Setting Up Ppp Under

Debian.

2.3 Partitioning Your Hard Drive

Before you install Debian on your computer, it is generally a good idea to plan how the contents of your hard drive will be arranged. One part of this process involves partitioning your hard drive.

2.3.1 Background

Partitioning your disk simply refers to the act of breaking up your disk into sections. Each section is then independent of the others. It’s roughly equivalent to putting up walls in a house; after that, adding furniture to one room doesn’t affect any other room.

If you already have an operating system on your system (Windows 95, Windows NT, DOS, etc.) and you want to install Debian GNU/Linux on the same disk, you will probably need to repartition the disk. In general, changing a partition that already has a filesystem on it will destroy any information in that filesystem. Therefore, you should always make backups before doing any repartitioning. Using the analogy of the house, you would probably want to move all the furniture out of the way before moving a wall or you risk destroying your furniture. Luckily, there is an alternative for some users; see

Section 2.3.6 on Page [*] for More Information.

At a bare minimum, GNU/Linux needs one partition for itself. You can have a single partition containing the entire operating system, applications, and your personal files. Most people choose to give GNU/Linux more than the minimum number of partitions, however. There are two reasons you might want to break up the filesystem into a number of smaller partitions. The first is for safety. If something happens to corrupt the filesystem, generally only one partition is affected. Thus, you only have to replace (from the backups you’ve been carefully keeping) a portion of your system. At the very least, you should consider creating what is commonly called a “root partition.” This contains the most essential components of the system. If any other partitions get corrupted, you can still boot into GNU/Linux to fix the system. This can save you the trouble of having to reinstall the system from scratch.

The second reason is generally more important in a business setting, but it really depends on your use of the machine. Suppose something runs out of control and starts eating disk space. If the process causing the problem happens to have root privileges (the system keeps a percentage of the disk away from users), you could suddenly find yourself out of disk space. This is not good since the operating system needs to use real files (besides swap space) for many things. It may not even be a problem of local origin. For example, unsolicited e-mail (“spam”) can easily fill a partition. By using more partitions, you protect the system from many of these problems. Using e-mail as an example again, by putting the directory /var/spool/mail on its own partition, the bulk of the system will /work even if unsolicited e-mail fills that partition.

Another reason applies only if you have a large IDE disk drive and are using neither LBA addressing nor overlay drivers. In this case, you will have to put the root partition into the first 1,024 cylinders of your hard drive, usually around 524 megabytes. See

Section 2.3.3 on Page [*] for More Information on This Issue.

See your hard drive manual for a description of these features.

Most people feel that a swap partition is also a necessity, although this isn’t strictly true. “Swap” is scratch space for an operating system, which allows the system to use disk storage as “virtual memory” in addition to physical memory. Putting swap on a separate partition allows Linux to make much more efficient use of it. It is possible to force Linux to use a regular file as swap, but this is not recommended.

The only real drawback to using more partitions is that it is often difficult to know in advance what your needs will be. If you make a partition too small, either you will have to reinstall the system, or you will be constantly moving things around to make room in the undersized partition. On the other hand, if you make the partition too big, you may be wasting space that could be used elsewhere.

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