3.6. Pre-Installation Hardware and Operating System Setup

This section will walk you through pre-installation hardware setup, if any, that you will need to do prior to installing Debian. Generally, this involves checking and possibly changing firmware settings for your system. The “firmware” is the core software used by the hardware; it is most critically invoked during the bootstrap process (after power-up). Known hardware issues affecting the reliability of Debian GNU/Linux on your system are also highlighted.

3.6.1. Invoking the BIOS Set-Up Menu

BIOS provides the basic functions needed to boot your machine to allow your operating system to access your hardware. Your system probably provides a BIOS setup menu, which is used to configure the BIOS. Before installing, you must ensure that your BIOS is set up correctly; not doing so can lead to intermittent crashes or an inability to install Debian.
The rest of this section is lifted from the http://www.faqs.org/faqs/pc-hardware-faq/part1/, answering the question, “How do I enter the CMOS configuration menu?”. How you access the BIOS (or “CMOS”) configuration menu depends on who wrote your BIOS software:

AMI BIOS

Delete key during the POST (power on self test)

Award BIOS

Ctrl+Alt+Esc, or Delete key during the POST

DTK BIOS

Esc key during the POST

IBM PS/2 BIOS

Ctrl+Alt+Insert after Ctrl+Alt+Delete

Phoenix BIOS

Ctrl+Alt+Esc or Ctrl+Alt+S or F1

Information on invoking other BIOS routines can be found in http://www.tldp.org/HOWTO/Hard-Disk-Upgrade/install.html.
Some 32-bit PC machines don't have a CMOS configuration menu in the BIOS. They require a software CMOS setup program. If you don't have the Installation and/or Diagnostics diskette for your machine, you can try using a shareware/freeware program. Try looking in ftp://ftp.simtel.net/pub/simtelnet/msdos/.

3.6.2. Boot Device Selection

Many BIOS setup menus allow you to select the devices that will be used to bootstrap the system. Set this to look for a bootable operating system on A: (the first floppy disk), then optionally the first CD-ROM device (possibly appearing as D: or E:), and then from C: (the first hard disk). This setting enables you to boot from either a floppy disk or a CD-ROM, which are the two most common boot devices used to install Debian.
If you have a newer SCSI controller and you have a CD-ROM device attached to it, you are usually able to boot from the CD-ROM. All you have to do is enable booting from a CD-ROM in the SCSI-BIOS of your controller.
Another popular option is to boot from a USB storage device (also called a USB memory stick or USB key). Some BIOSes can boot directly from a USB storage device, but some cannot. You may need to configure your BIOS to boot from a “Removable drive” or even from “USB-ZIP” to get it to boot from the USB device.
Here are some details about how to set the boot order. Remember to reset the boot order after Linux is installed, so that you restart your machine from the hard drive.

3.6.2.1. Changing the Boot Order on IDE Computers

1. As your computer starts, press the keys to enter the BIOS utility. Often, it is the Delete key. However, consult the hardware documentation for the exact keystrokes.
2. Find the boot sequence in the setup utility. Its location depends on your BIOS, but you are looking for a field that lists drives.
   Common entries on IDE machines are C, A, cdrom or A, C, cdrom.
   C is the hard drive, and A is the floppy drive.
   
3. Change the boot sequence setting so that the CD-ROM or the floppy is first. Usually, the Page Up or Page Down keys cycle through the possible choices.
4. Save your changes. Instructions on the screen tell you how to save the changes on your computer.

3.6.2.2. Changing the Boot Order on SCSI Computers

1. As your computer starts, press the keys to enter the SCSI setup utility.
   You can start the SCSI setup utility after the memory check and the message about how to start the BIOS utility displays when you start your computer.
   The keystrokes you need depend on the utility. Often, it is Ctrl+F2. However, consult your hardware documentation for the exact keystrokes.
   
2. Find the utility for changing the boot order.
3. Set the utility so that the SCSI ID of the CD drive is first on the list.
4. Save your changes. Instructions on the screen tell you how to save the changes on your computer. Often, you must press F10.

3.6.3. Miscellaneous BIOS Settings

3.6.3.1. CD-ROM Settings

Some BIOS systems (such as Award BIOS) allow you to automatically set the CD speed. You should avoid that, and instead set it to, say, the lowest speed. If you get seek failed error messages, this may be your problem.

3.6.3.2. Extended vs. Expanded Memory

If your system provides both extended and expanded memory, set it so that there is as much extended and as little expanded memory as possible. Linux requires extended memory and cannot use expanded memory.

3.6.3.3. Virus Protection

Disable any virus-warning features your BIOS may provide. If you have a virus-protection board or other special hardware, make sure it is disabled or physically removed while running GNU/Linux. These aren't compatible with GNU/Linux; moreover, due to the file system permissions and protected memory of the Linux kernel, viruses are almost unheard of^[5].

3.6.3.4. Shadow RAM

Your motherboard may provide shadow RAM or BIOS caching. You may see settings for “Video BIOS Shadow”, “C800-CBFF Shadow”, etc. Disable all shadow RAM. Shadow RAM is used to accelerate access to the ROMs on your motherboard and on some of the controller cards. Linux does not use these ROMs once it has booted because it provides its own faster 32-bit software in place of the 16-bit programs in the ROMs. Disabling the shadow RAM may make some of it available for programs to use as normal memory. Leaving the shadow RAM enabled may interfere with Linux access to hardware devices.

3.6.3.5. Memory Hole

If your BIOS offers something like “15–16 MB Memory Hole”, please disable that. Linux expects to find memory there if you have that much RAM.
We have a report of an Intel Endeavor motherboard on which there is an option called “LFB” or “Linear Frame Buffer”. This had two settings: “Disabled” and “1 Megabyte”. Set it to “1 Megabyte”. When disabled, the installation floppy was not read correctly, and the system eventually crashed. At this writing we don't understand what's going on with this particular device — it just worked with that setting and not without it.

3.6.3.6. Advanced Power Management

If your motherboard provides Advanced Power Management (APM), configure it so that power management is controlled by APM. Disable the doze, standby, suspend, nap, and sleep modes, and disable the hard disk's power-down timer. Linux can take over control of these modes, and can do a better job of power-management than the BIOS.

3.6.4. Hardware Issues to Watch Out For

USB BIOS support and keyboards.  If you have no AT-style keyboard and only a USB model, you may need to enable legacy AT keyboard emulation in your BIOS setup. Only do this if the installation system fails to use your keyboard in USB mode. Conversely, for some systems (especially laptops) you may need to disable legacy USB support if your keyboard does not respond. Consult your main board manual and look in the BIOS for “Legacy keyboard emulation” or “USB keyboard support” options.

---

^[5] After installation you can enable Boot Sector protection if you want. This offers no additional security in Linux but if you also run Windows it may prevent a catastrophe. There is no need to tamper with the Master Boot Record (MBR) after the boot manager has been set up.

3.5. Pre-Partitioning for Multi-Boot Systems

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 inside a house; if you add furniture to one room it doesn't affect any other room.
If you already have an operating system on your system (Windows 9x, Windows NT/2000/XP/2003/Vista/7, OS/2, MacOS, Solaris, FreeBSD, …) and want to stick Debian on the same disk, you will need to repartition the disk. Debian requires its own hard disk partitions. It cannot be installed on Windows or MacOS partitions. It may be able to share some partitions with other Unix systems, but that's not covered here. At the very least you will need a dedicated partition for the Debian root.
You can find information about your current partition setup by using a partitioning tool for your current operating system, such as fdisk or PartitionMagic. Partitioning tools always provide a way to show existing partitions without making changes.
In general, changing a partition with a file system already on it will destroy any information there. Thus 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 it.
If your computer has more than one hard disk, you may want to dedicate one of the hard disks completely to Debian. If so, you don't need to partition that disk before booting the installation system; the installer's included partitioning program can handle the job nicely.
If your machine has only one hard disk, and you would like to completely replace the current operating system with Debian GNU/Linux, you also can wait to partition as part of the installation process (Section 6.3.3, “Partitioning and Mount Point Selection”), after you have booted the installation system. However this only works if you plan to boot the installer system from tapes, CD-ROM or files on a connected machine. Consider: if you boot from files placed on the hard disk, and then partition that same hard disk within the installation system, thus erasing the boot files, you'd better hope the installation is successful the first time around. At the least in this case, you should have some alternate means of reviving your machine like the original system's installation tapes or CDs.
If your machine already has multiple partitions, and enough space can be provided by deleting and replacing one or more of them, then you too can wait and use the Debian installer's partitioning program. You should still read through the material below, because there may be special circumstances like the order of the existing partitions within the partition map, that force you to partition before installing anyway.
If your machine has a FAT or NTFS filesystem, as used by DOS and Windows, you can wait and use Debian installer's partitioning program to resize the filesystem.
If none of the above apply, you'll need to partition your hard disk before starting the installation to create partitionable space for Debian. If some of the partitions will be owned by other operating systems, you should create those partitions using native operating system partitioning programs. We recommend that you do not attempt to create partitions for Debian GNU/Linux using another operating system's tools. Instead, you should just create the native operating system's partitions you will want to retain.
If you are going to install more than one operating system on the same machine, you should install all other system(s) before proceeding with Debian installation. Windows and other OS installations may destroy your ability to start Debian, or encourage you to reformat non-native partitions.
You can recover from these actions or avoid them, but installing the native system first saves you trouble.
If you currently have one hard disk with one partition (a common setup for desktop computers), and you want to multi-boot the native operating system and Debian, you will need to:

1. Back up everything on the computer.
2. Boot from the native operating system installer media such as CD-ROM or tapes.
3. Use the native partitioning tools to create native system partition(s). Leave either a place holder partition or free space for Debian GNU/Linux.
4. Install the native operating system on its new partition.
5. Boot back into the native system to verify everything's OK, and to download the Debian installer boot files.
6. Boot the Debian installer to continue installing Debian.

3.5.1. Partitioning From DOS or Windows

If you are manipulating existing FAT or NTFS partitions, it is recommended that you either use the scheme below or native Windows or DOS tools. Otherwise, it is not really necessary to partition from DOS or Windows; the Debian partitioning tools will generally do a better job.
But if you have a large IDE disk, and are not using LBA addressing, overlay drivers (sometimes provided by hard disk manufacturers), or a new (post 1998) BIOS that supports large disk access extensions, then you must locate your Debian boot partition carefully. In this case, you will have to put the boot partition into the first 1024 cylinders of your hard disk (usually around 524 megabytes, without BIOS translation). This may require that you move an existing FAT or NTFS partition.

3.5.1.1. Lossless Repartitioning When Starting From DOS, Win-32 or OS/2

One of the most common installations is onto a system that already contains DOS (including Windows 3.1), Win32 (such as Windows 95, 98, Me, NT, 2000, XP, 2003, Vista, 7), or OS/2, and it is desired to put Debian onto the same disk without destroying the previous system. Note that the installer supports resizing of FAT and NTFS filesystems as used by DOS and Windows. Simply start the installer and when you get to the partitioning step, select the option for Manual partitioning, select the partition to resize, and specify its new size. So in most cases you should not need to use the method described below.
Before going any further, you should have decided how you will be dividing up the disk. The method in this section will only split a partition into two pieces. One will contain the original OS and the other will be used for Debian. During the installation of Debian, you will be given the opportunity to use the Debian portion of the disk as you see fit, i.e., as swap or as a file system.
The idea is to move all the data on the partition to the beginning, before changing the partition information, so that nothing will be lost. It is important that you do as little as possible between the data movement and repartitioning to minimize the chance of a file being written near the end of the partition as this will decrease the amount of space you can take from the partition.
The first thing needed is a copy of fips. Unzip the archive and copy the files RESTORRB.EXE, FIPS.EXE and ERRORS.TXT to a bootable floppy. A bootable floppy can be created using the command sys a: under DOS. fips comes with very good documentation which you may want to read. You will definitely need to read the documentation if you use a disk compression driver or a disk manager. Create the disk and read the documentation before you defragment the disk.
The next thing needed is to move all the data to the beginning of the partition. defrag, which comes standard with DOS 6.0 and later, can easily do the job. See the fips documentation for a list of other software that may do the trick. Note that if you have Windows 9x, you must run defrag from there, since DOS doesn't understand VFAT, which is used to support for long filenames, used in Windows 95 and higher.
After running the defragmenter (which can take a while on a large disk), reboot with the fips disk you created in the floppy drive. Simply type a:\fips and follow the directions.
Note that there are many other partition managers out there, in case fips doesn't do the trick for you.

3.5.1.2. Partitioning for DOS

If you are partitioning for DOS drives, or changing the size of DOS partitions, using Debian tools, many people experience problems working with the resulting FAT partitions. For instance, some have reported slow performance, consistent problems with scandisk, or other weird errors in DOS or Windows.
Apparently, whenever you create or resize a partition for DOS use, it's a good idea to fill the first few sectors with zeros. You should do this prior to running DOS's format command by executing the following command from Debian:

3.4. Meeting Minimum Hardware Requirements

Once you have gathered information about your computer's hardware, check that your hardware will let you do the type of installation that you want to do.
Depending on your needs, you might manage with less than some of the recommended hardware listed in the table below. However, most users risk being frustrated if they ignore these suggestions.
A Pentium 4, 1GHz system is the minimum recommended for a desktop system.

Table 3.2. Recommended Minimum System Requirements

Install Type	RAM (minimal)	RAM (recommended)	Hard Drive
No desktop	64 megabytes	256 megabytes	1 gigabyte
With Desktop	128 megabytes	512 megabytes	5 gigabytes

The actual minimum memory requirements are a lot less then the numbers listed in this table. Depending on the architecture, it is possible to install Debian with as little as 20MB (for s390) to 60MB (for amd64). The same goes for the disk space requirements, especially if you pick and choose which applications to install; see Section D.2, “Disk Space Needed for Tasks” for additional information on disk space requirements.
It is possible to run a graphical desktop environment on older or low-end systems, but in that case it is recommended to install a window manager that is less resource-hungry than those of the GNOME or KDE desktop environments; alternatives include xfce4, icewm and wmaker, but there are others to choose from.
It is practically impossible to give general memory or disk space requirements for server installations as those very much depend on what the server is to be used for.
Remember that these sizes don't include all the other materials which are usually to be found, such as user files, mail, and data. It is always best to be generous when considering the space for your own files and data.
Disk space required for the smooth operation of the Debian GNU/Linux system itself is taken into account in these recommended system requirements. Notably, the /var partition contains a lot of state information specific to Debian in addition to its regular contents, like logfiles. The dpkg files (with information on all installed packages) can easily consume 40MB. Also, apt-get puts downloaded packages here before they are installed. You should usually allocate at least 200MB for /var, and a lot more if you install a graphical desktop environment.

3.3. Information You Will Need

3.3.1. Documentation

3.3.1.1. Installation Manual

The document you are now reading, which is the official version of the Installation Guide for the squeeze release of Debian; available in various formats and translations.

3.3.1.2. Hardware documentation

Often contains useful information on configuring or using your hardware.

• Linux Hardware Compatibility HOWTO

3.3.2. Finding Sources of Hardware Information

In many cases, the installer will be able to automatically detect your hardware. But to be prepared, we do recommend familiarizing yourself with your hardware before the install.
Hardware information can be gathered from:

• The manuals that come with each piece of hardware.
• The BIOS setup screens of your computer. You can view these screens when you start your computer by pressing a combination of keys. Check your manual for the combination. Often, it is the Delete key.
• The cases and boxes for each piece of hardware.
• The System window in the Windows Control Panel.
• System commands or tools in another operating system, including file manager displays. This source is especially useful for information about RAM and hard drive memory.
• Your system administrator or Internet Service Provider. These sources can tell you the settings you need to set up your networking and e-mail.

Table 3.1. Hardware Information Needed for an Install

Hardware	Information You Might Need
Hard Drives	How many you have.
	Their order on the system.
	Whether IDE (also known as PATA), SATA or SCSI.
	Available free space.
	Partitions.
	Partitions where other operating systems are installed.
Monitor	Model and manufacturer.
	Resolutions supported.
	Horizontal refresh rate.
	Vertical refresh rate.
	Color depth (number of colors) supported.
	Screen size.
Mouse	Type: serial, PS/2, or USB.
	Port.
	Manufacturer.
	Number of buttons.
Network	Model and manufacturer.
	Type of adapter.
Printer	Model and manufacturer.
	Printing resolutions supported.
Video Card	Model and manufacturer.
	Video RAM available.
	Resolutions and color depths supported (these should be checked against your monitor's capabilities).

3.3.3. Hardware Compatibility

Many brand name products work without trouble on Linux. Moreover, hardware support in Linux is improving daily. However, Linux still does not run as many different types of hardware as some operating systems.
In particular, Linux usually cannot run hardware that requires a running version of Windows to work.
Although some Windows-specific hardware can be made to run on Linux, doing so usually requires extra effort. In addition, Linux drivers for Windows-specific hardware are usually specific to one Linux kernel. Therefore, they can quickly become obsolete.
So called win-modems are the most common type of this hardware. However, printers and other equipment may also be Windows-specific.
You can check hardware compatibility by:

• Checking manufacturers' web sites for new drivers.
• Looking at web sites or manuals for information about emulation. Lesser known brands can sometimes use the drivers or settings for better-known ones.
• Checking hardware compatibility lists for Linux on web sites dedicated to your architecture.
• Searching the Internet for other users' experiences.

3.3.4. Network Settings

If your computer is connected to a network 24 hours a day (i.e., an Ethernet or equivalent connection — not a PPP connection), you should ask your network's system administrator for this information.

• Your host name (you may be able to decide this on your own).
• Your domain name.
• Your computer's IP address.
• The netmask to use with 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.

On the other hand, if your administrator tells you that a DHCP server is available and is recommended, then you don't need this information because the DHCP server will provide it directly to your computer during the installation process.
If you use a wireless network, you should also find out:

• ESSID of your wireless network.
• WEP security key (if applicable).

3.2. Back Up Your Existing Data!

Before you start, make sure to back up every file that is now on your system. If this is the first time a non-native operating system has been installed on your computer, it's quite likely you will need to re-partition your disk to make room for Debian GNU/Linux. Anytime you partition your disk, you run a risk of losing everything on the disk, no matter what program you use to do it. The programs used in installation are quite reliable and most have seen years of use; but they are also quite powerful and 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.
If you are creating a multi-boot system, make sure that you have the distribution media of any other present operating systems on hand. Especially if you repartition your boot drive, you might find that you have to reinstall your operating system's boot loader, or in many cases the whole operating system itself and all files on the affected partitions.

3.1. Overview of the Installation Process

First, just a note about re-installations. With Debian, a circumstance that will require a complete re-installation of your system is very rare; perhaps mechanical failure of the hard disk would be the most common case.
Many common operating systems may require a complete installation to be performed when critical failures take place or for upgrades to new OS versions. Even if a completely new installation isn't required, often the programs you use must be re-installed to operate properly in the new OS.
Under Debian GNU/Linux, it is much more likely that your OS can be repaired rather than replaced if things go wrong. Upgrades never require a wholesale installation; you can always upgrade in-place. And the programs are almost always compatible with successive OS releases. If a new program version requires newer supporting software, the Debian packaging system ensures that all the necessary software is automatically identified and installed. The point is, much effort has been put into avoiding the need for re-installation, so think of it as your very last option. The installer is not designed to re-install over an existing system.
Here's a road map for the steps you will take during the installation process.

1. Back up any existing data or documents on the hard disk where you plan to install.
2. Gather information about your computer and any needed documentation, before starting the installation.
3. Create partitionable space for Debian on your hard disk.
4. Locate and/or download the installer software and any specialized driver files your machine requires (except Debian CD users).
5. Set up boot tapes/floppies/USB sticks, or place boot files (most Debian CD users can boot from one of the CDs).
6. Boot the installation system.
7. Select the installation language.
8. Activate the ethernet network connection, if available.
9. Create and mount the partitions on which Debian will be installed.
10. Watch the automatic download/install/setup of the base system.
11. Install a boot loader which can start up Debian GNU/Linux and/or your existing system.
12. Load the newly installed system for the first time.

For 32-bit PC you have the option of using a graphical version of the installation system. For more information about this graphical installer, see Section D.6, “The Graphical Installer”.
If you have problems during the installation, it helps to know which packages are involved in which steps. Introducing the leading software actors in this installation drama:
The installer software, debian-installer, is the primary concern of this manual. It detects hardware and loads appropriate drivers, uses dhcp-client to set up the network connection, runs debootstrap to install the base system packages, and runs tasksel to allow you to install certain additional software. Many more actors play smaller parts in this process, but debian-installer has completed its task when you load the new system for the first time.
To tune the system to your needs, tasksel allows you to choose to install various predefined bundles of software like a Web server or a Desktop environment.
One important option during the installation is whether or not to install a graphical desktop environment, consisting of the X Window System and one of the available graphical desktop environments. If you choose not to select the “Desktop environment” task, you will only have a relatively basic, command line driven system. Installing the Desktop environment task is optional because it requires a fairly large amount of disk space, and because many Debian GNU/Linux systems are servers which don't really have any need for a graphical user interface to do their job.
Just be aware that the X Window System is completely separate from debian-installer, and in fact is much more complicated. Installation and troubleshooting of the X Window System is not within the scope of this manual.

2.5. Memory and Disk Space Requirements

You must have at least 56MB of memory and 650MB of hard disk space to perform a normal installation. Note that these are fairly minimal numbers. For more realistic figures, see Section 3.4, “Meeting Minimum Hardware Requirements”.
Installation on systems with less memory^[4] or disk space available may be possible but is only advised for experienced users.

---

^[4] Installation images that support the graphical installer require more memory than images that support only the textual installer and should not be used on systems with less than 56MB of memory. If there is a choice between booting the regular and the graphical installer, the former should be selected.