Subject to limitations in some cases, you may boot the installation system from a Debian GNU/Linux CD-ROM, floppy disks, a partition on a hard disk, or from another machine via a local area network.
Boot parameters are Linux kernel parameters which are generally used to make sure that peripherals are dealt with properly. For the most part, the kernel can auto-detect information about your peripherals. However, in some cases you'll have to help the kernel a bit.
If you are booting from the rescue floppy or from CD-ROM you will be presented
with the boot prompt, boot:. Details about how to use boot
parameters with the rescue floppy can be found in Booting from Floppies,
Section 5.3. If you are booting from an existing operating system, you'll
have to use other means to set boot parameters. For instance, if you are
installing from DOS, you can edit the install.bat
file with any
text editor.
Full information on boot parameters can be found in the Linux BootPrompt
HOWTO
; this section contains only a sketch of the most salient
parameters.
If this is the first time you're booting the system, try the default boot parameters (i.e., don't try setting arguments) 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.
When the kernel boots, a message Memory: availk/totalk available should be emitted early in the process. total should match the total amount of RAM, in kilobytes. If this doesn't match the actual of RAM you have installed, you need to use the mem=ram parameter, where ram is set to the amount of memory, suffixed with ``k'' for kilobytes, or ``m'' for megabytes. For example, both mem=65536k and mem=64m mean 64MB of RAM.
Some systems have floppies with ``inverted DCLs''. If you receive errors reading from the floppy, even when you know the floppy is good, try the parameter floppy=thinkpad.
On some systems, such as the IBM PS/1 or ValuePoint (which have ST-506 disk drivers), the IDE drive may not be properly recognized. Again, try it first without the parameters and see if the IDE drive is recognized properly. If not, determine your drive geometry (cylinders, heads, and sectors), and use the parameter hd=cylinders,heads,sectors.
If your monitor is only capable of black-and-white, use the mono boot argument. Otherwise, your installation will use color, which is the default.
If you are booting with a serial console, generally the kernel will autodetect this . If you have a videocard (framebuffer) and a keyboard also attached to the computer which you wish to boot via serial console, you may have to pass the console=device argument to the kernel, where device is your serial device, which is usually something like ``ttyS0''.
Again, full details on boot parameters can be found in the Linux BootPrompt
HOWTO
, including tips for obscure hardware. Some common gotchas are
included below in Troubleshooting the
Install Process, Section 5.6.
The installation system recognizes a few boot arguments which may be useful. The effects of quiet and verbose are listed in Effects of Verbose and Quiet, Section 11.5.
The easiest route for most people will be to use a set of Debian CDs
. If you
have a CD set, and if your machine supports booting directly off the CD, great!
Simply configure your system for booting off a CD as described in Boot Device Selection, Section
3.6.2, insert your CD, reboot, and proceed to the next chapter.
You may need to configure your hardware as indicated in Boot Device Selection, Section 3.6.2. Then put the CD-ROM into the drive, and reboot. The system should boot up, and you should be presented with the boot: prompt. Here you can enter your boot arguments, or just hit enter.
Note that official Debian CD-ROM sets for Intel x86 will boot different ``flavors'' depending on which CD-ROM you boot from. See Choosing the Right Installation Set, Section 4.2.2 for a discussion of the different flavors. Here's how the flavors are laid out on the different CD-ROMs:
So, if you want to boot from one of the above flavors, put that CD in the drive
for booting. If your system can't boot directly from CD-ROM, or you simply
can't seem to get it to work, don't despair; you can simply run
E:\install\boot.bat
under DOS (replace E: with
whatever drive letter DOS assigns to your CD-ROM drive) to start the
installation process.
Execute the boot.bat
file which is located in the
\boot
directory on your CD. Then, skip down to Booting Into Your New Debian System, Chapter
8.
Also, if you're going to be installing from a FAT (DOS) partition, you have the option of booting the installer from the hard disk. See Booting from a DOS partition, Section 5.4.1 below for more information on installing via this method.
Note that certain CD drives may require special drivers, and so be inaccessible in the early installation stages. If it turns out the standard way of booting off a CD doesn't work for your hardware, revisit this chapter and read about alternate kernels and installation methods which may work for you.
Even if you cannot boot from CD-ROM, you can probably install the Debian system components and any packages you want from CD-ROM. Simply boot using a different media, such as floppies. When it's time to install the operating system, base system, and any additional packages, point the installation system at the CD-ROM drive.
If you have problems booting, see Troubleshooting the Install Process, Section 5.6.
Booting from floppies is supported for Intel x86.
You will have already downloaded the floppy images you needed and created floppies from the images in Creating Floppies from Disk Images, Section 4.3. If you need to, you can also modify the rescue floppy; see Replacing the Rescue Floppy Kernel, Section 10.3.
Booting from the rescue floppy is easy: place the rescue floppy in the primary floppy drive, and shut down the system as you normally would, then turn it back on.
Note that on some machines, Control-Alt-Delete does not properly reset the machine, so a ``hard'' reboot is recommended. If you are installing from an existing operating system (e.g., from a DOS box) you don't have a choice. Otherwise, please do a hard reboot when booting.
The floppy disk will be accessed, and you should then see a screen that introduces the rescue floppy and ends with the boot: prompt.
If you are using an alternative way to boot the system, follow the instructions, and wait for the boot: prompt to come up. If you boot from floppies smaller than 1.44MB, or, in fact, whenever you boot from floppy on your architecture, you have to use a ramdisk boot method, and you will need the Root Disk.
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.
Information on boot parameters which might be useful can be found by pressing F4 and F5. If you add any parameters to the boot command line, be sure to type the boot method (the default is linux) and a space before the first parameter (e.g., linux floppy=thinkpad). If you simply press Enter, that's the same as typing linux without any special parameters.
The disk is 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. Pressing F3 will give further information on how to use the rescue floppy.
Once you press Enter, you should see the message Loading..., followed by Uncompressing Linux..., and then a screenful or so of information about the hardware in your system. More information on this phase of the boot process can be found below in Interpreting the Kernel Startup Messages, Section 5.6.3.
If you choose a non-default boot method, e.g., ``ramdisk'' or ``floppy'', you will be prompted to insert the Root Floppy. Insert the Root Floppy into the first disk drive and press Enter. (If you choose floppy1 insert the Root Floppy into the second disk drive.)
After booting from the rescue floppy, the root floppy is requested. Insert the
root floppy and press Enter, and the contents are loaded into memory.
The installer program dbootstrap
is automatically launched.
If you have problems booting, see Troubleshooting the Install Process, Section 5.6.
Booting from an existing operating system is often a convenient option; for some systems it is the only supported method of installation.
To boot the installer from hard disk, you will have already completed downloading and placing the needed files in Preparing Files for Hard Disk Booting, Section 4.4.
Boot into DOS (not Windows) without any drivers being loaded. To do this, you
have to press F8 at exactly the right moment (and optionally select
the `safe mode command prompt only' option). Enter the subdirectory for the
flavor you chose, e.g., cd c:\current\compact. Next, execute
install.bat
. The kernel will load and launch the installer
system.
Booting from the network requires that you have a network connection supported by the boot floppies, including either a static network address or a DHCP server, a RARP or a BOOTP server, and a TFTP server. The installation method to support TFTP booting is described in Preparing Files for TFTP Net Booting, Section 4.5.
The biggest problem for people installing Debian for the first time seems to be floppy disk reliability.
The rescue floppy is the floppy with the worst problems, because it is read by the hardware directly, before Linux boots. Often, the hardware doesn't read as reliably as the Linux floppy disk driver, and may just stop without printing an error message if it reads incorrect data. There can also be failures in the Driver Floppies most of which indicate themselves with a flood of messages about disk I/O errors.
If you are having the installation stall at a particular floppy, the first thing you should do is re-download the floppy disk image and write it to a different floppy. Simply reformatting the old floppy may not be sufficient, even if it appears that the floppy was reformatted and written with no errors. It is sometimes useful to try writing the floppy on a different system.
One user reports he had to write the images to floppy three times before one worked, and then everything was fine with the third floppy.
Other users have reported that simply rebooting a few times with the same floppy in the floppy drive can lead to a successful boot. This is all due to buggy hardware or firmware floppy drivers.
If you have problems and the kernel hangs during the boot process, doesn't recognize peripherals you actually have, or drives are not recognized properly, the first thing to check is the boot parameters, as discussed in Boot Parameter Arguments, Section 5.1.
Often, problems can be solved by removing add-ons and peripherals, and then trying booting again. Internal modems, sound cards, and Plug-n-Play devices can be especially problematic.
There are, however, some limitations in our boot floppy set with respect to supported hardware. Some Linux-supported platforms might not be directly supported by our boot floppies. If this is the case, you may have to create a custom rescue disk (see Replacing the Rescue Floppy Kernel, Section 10.3), or investigate network installations.
If you have a large amount of memory installed in your machine, more than 512M, and the installer hangs when booting the kernel, you may need to include a boot argument to limit the amount of memory the kernel sees, such as mem=512m.
If you have a very old machine, and the kernel hangs after saying Checking 'hlt' instruction..., then you should try the no-hlt boot argument, which disables this test.
During the boot sequence, you may see 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 kernel for the installation system 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 later (see Compiling a New Kernel, Section 9.5).
dbootstrap
Problem Report
If you get through the initial boot phase but cannot complete the install,
dbootstrap
's 'Report a Problem' menu choice may be helpful. It
creates dbg_log.tgz
on a floppy, hard disk or nfs-mounted
filesystem. dbg_log.tgz
details the system's state
(/var/log/messages
, /proc/cpuinfo
etc.).
dbg_log.tgz
may provide clues as to what went wrong and how to fix
it. If you are submitting a bug report you may want to attach this file to the
bug report.
If you still have problems, please submit a bug report. Send an email to
submit@bugs.debian.org
. You
must include the following as the first lines of the email:
Package: boot-floppies Version: version
Make sure you fill in version with the version of the boot-floppies set that you used. If you don't know the version, use the date you downloaded the floppies, and include the distribution you got them from (e.g., ``stable'', ``frozen'', ``woody'').
You should also include the following information in your bug report:
flavor: flavor of image you are using architecture: i386 model: your general hardware vendor and model memory: amount of RAM scsi: SCSI host adapter, if any cd-rom: CD-ROM model and interface type, e.g., ATAPI network card: network interface card, if any pcmcia: details of any PCMCIA devices
Depending on the nature of the bug, it also might be useful to report whether you are installing to IDE or SCSI disks, other peripheral devices such as audio, disk capacity, and the model of video card.
In the bug report, describe what the problem is, including the last visible kernel messages in the event of a kernel hang. Describe the steps that you did which brought the system into the problem state.
dbootstrap
dbootstrap
is the name of the program which is run after you have
booted into the installation system. It is responsible for initial system
configuration and the installation of the ``base system''.
The main job of dbootstrap
, and the main purpose of your initial
system configuration, is to configure essential elements of your system. For
instance, you may need to use certain ``kernel modules'', drivers which are
linked into the kernel. These modules include storage hardware drivers,
network drivers, special language support, and support for other peripherals
which are not automatically built in to the kernel you are using.
Disk partitioning, disk formatting, and networking setup are also facilitated
by dbootstrap
. This fundamental setup is done first, since it is
often necessary for the proper functioning of your system.
dbootstrap
is a simple, character-based application, designed for
maximum compatibility in all situations (such as installation over a serial
line). It is very easy to use. It will guide you through each step of the
installation process in a linear fashion. You can also go back and repeat
steps if you find you have made a mistake.
Navigation within dbootstrap
is accomplished with the arrow keys,
Enter, and Tab.
If you are an experienced Unix or Linux user, press Left Alt-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 Left Alt-F1 to get back to menus. Linux
provides up to 64 virtual consoles, although the rescue floppy only uses a few
of them.
Error messages are redirected to the third virtual terminal (known as
tty3). You can access this terminal by pressing Left
Alt-F3 (hold the Alt key while pressing the F3 function
key); get back to dbootstrap
with Left Alt-F1.
These messages can also be found in /var/log/messages
. After
installation, this log is copied to /var/log/installer.log
on your
new system.
During the Base installation, package unpacking and setup messages are
redirected to tty4. You can access this terminal by pressing
Left Alt-F4; get back to dbootstrap
with Left
Alt-F1.
The unpack/setup messages generated by debootstrap are saved in
/target/tmp/debootstrap.log
when the installation is performed
over a serial console.
The first screen dbootstrap
will present you with is the ``Release
Notes''. This screen presents the version information for the
boot-floppies
software you are using, and gives a brief
introduction to Debian developers.
You may see a dialog box that says ``The installation program is determining
the current state of your system and the next installation step that should be
performed.''. 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,
dbootstrap
, 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, in case 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 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, entitled ``Debian GNU/Linux Installation Main Menu''. The choices at the
top of the menu will change to indicate your progress in installing the system.
Phil Hughes wrote in the Linux
Journal
that you could teach a chicken to install Debian!
He meant that the installation process was mostly just pecking at the
Enter 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 step in
installing the system will be taken.
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 installation is
complete, you'll be able to select a keyboard layout from a wider range of
choices (run kbdconfig
as root when you have completed the
installation).
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. An 'extended' keyboard is one with F1 through F10 keys along the top row.
If you are installing a diskless workstation, the next few steps will be skipped, since there are no local disks to partition. In that case, your next step will be ``Configure the Network'', Section 7.7. After that, you will be prompted to mount your NFS root partition in ``Mount a Previously-Initialized Partition'', Section 6.9.
Did we tell you to back up your disks? Here's 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.
Installing Debian GNU/Linux 3.0 For Intel x86
version 3.0.22, 14 March, 2002