| D.3. Installation af Debian GNU/Linux fra et Unix/Linux-system | ||
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Appendiks D. Diverse forklaringer | 
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| D.3. Installation af Debian GNU/Linux fra et Unix/Linux-system | ||
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Appendiks D. Diverse forklaringer |
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Dette afsnit forklarer hvordan Debian GNU/Linux installeres fra et eksisterende Unix- eller Linuxsystem, uden brug af det menudrevne installationsprogram, som beskrevet i resten af manualen. Denne “cross-install”-manual er ønsket af brugere, der skifter til Debian GNU/Linux fra Red Hat, Mandriva og SUSE. I dette afsnit antages det at du kender til indtastning af *nix-kommandoer og navigering i filsystemet. I dette afsnit symboliserer $ en kommando til indtastning i brugerens nuværende system, mens # refererer til en kommando indtastet i Debian-chrooten.
Once you've got the new Debian system configured to your preference, you can migrate your existing user data (if any) to it, and keep on rolling. This is therefore a “zero downtime” Debian GNU/Linux install. It's also a clever way for dealing with hardware that otherwise doesn't play friendly with various boot or installation media.
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Bemærk |
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As this is a mostly manual procedure, you should bear in mind that you will need to do a lot of basic configuration of the system yourself, which will also require more knowledge of Debian and of Linux in general than performing a regular installation. You cannot expect this procedure to result in a system that is identical to a system from a regular installation. You should also keep in mind that this procedure only gives the basic steps to set up a system. Additional installation and/or configuration steps may be needed. |
With your current *nix partitioning tools, repartition the hard drive as needed, creating at least one filesystem plus swap. You need around 506MB of space available for a console only install, or about 1536MB if you plan to install X (more if you intend to install desktop environments like GNOME or KDE).
Next, create file systems on the partitions. For example, to create an ext3 file system on partition /dev/sda6 (that's our example root partition):
# mke2fs -j /dev/sda6
To create an ext2 file system instead, omit -j.
Initialize and activate swap (substitute the partition number for your intended Debian swap partition):
# mkswap /dev/sda5# sync # swapon /dev/sda5
Mount one partition as /mnt/debinst (the installation point, to be the root (/) filesystem on your new system). The mount point name is strictly arbitrary, it is referenced later below.
# mkdir /mnt/debinst
# mount /dev/sda6 /mnt/debinst
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Bemærk |
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If you want to have parts of the filesystem (e.g. /usr) mounted on separate partitions, you will need to create and mount these directories manually before proceding with the next stage. |
The utility used by the Debian installer, and recognized as the official way to install a Debian base system, is debootstrap. It uses wget and ar, but otherwise depends only on /bin/sh and basic Unix/Linux tools[26]. Install wget and ar if they aren't already on your current system, then download and install debootstrap.
Or, you can use the following procedure to install it manually. Make a work folder for extracting the .deb into:
# mkdir work # cd work
The debootstrap binary is located in the Debian archive (be sure to select the proper file for your architecture). Download the debootstrap .deb from the pool, copy the package to the work folder, and extract the files from it. You will need to have root privileges to install the files.
# ar -x debootstrap_0.X.X_all.deb # cd / # zcat /full-path-to-work/work/data.tar.gz | tar xv
debootstrap can download the needed files directly from the archive when you run it. You can substitute any Debian archive mirror for http.us.debian.org/debian in the command example below, preferably a mirror close to you network-wise. Mirrors are listed at http://www.debian.org/mirror/list.
If you have a jessie Debian GNU/Linux CD mounted at /cdrom, you could substitute a file URL instead of the http URL: file:/cdrom/debian/
Substitute one of the following for ARCH in the debootstrap command: amd64, arm64, armel, armhf, i386, mips, mipsel, powerpc, ppc64el, or s390x.
# /usr/sbin/debootstrap --arch ARCH jessie \
/mnt/debinst http://ftp.us.debian.org/debian
Now you've got a real Debian system, though rather lean, on disk. chroot into it:
# LANG=C.UTF-8 chroot /mnt/debinst /bin/bash
After chrooting you may need to set the terminal definition to be compatible with the Debian base system, for example:
# export TERM=xterm-color
Depending on the value of TERM, you may have to install the ncurses-term package to get support for it.
At this point /dev/ only contains very basic device files. For the next steps of the installation additional device files may be needed. There are different ways to go about this and which method you should use depends on the host system you are using for the installation, on whether you intend to use a modular kernel or not, and on whether you intend to use dynamic (e.g. using udev) or static device files for the new system.
Nogle få af de tilgængelige indstillinger:
installer pakken makedev, og opret et standardsæt af statiske enhedsfiler der bruger (efter chrooting)
# apt-get install makedev # mount none /proc -t proc # cd /dev # MAKEDEV generic
manuelt opret kun specifikke enhedsfiler der bruger MAKEDEV
bind mount /dev from your host system on top of /dev in the target system; note that the postinst scripts of some packages may try to create device files, so this option should only be used with care
You need to create /etc/fstab.
# editor /etc/fstab
Here is a sample you can modify to suit:
# /etc/fstab: static file system information. # # file system mount point type options dump pass /dev/XXX / ext3 defaults 0 1 /dev/XXX /boot ext3 ro,nosuid,nodev 0 2 /dev/XXX none swap sw 0 0 proc /proc proc defaults 0 0 /dev/fd0 /media/floppy auto noauto,rw,sync,user,exec 0 0 /dev/cdrom /media/cdrom iso9660 noauto,ro,user,exec 0 0 /dev/XXX /tmp ext3 rw,nosuid,nodev 0 2 /dev/XXX /var ext3 rw,nosuid,nodev 0 2 /dev/XXX /usr ext3 rw,nodev 0 2 /dev/XXX /home ext3 rw,nosuid,nodev 0 2
Use mount -a to mount all the file systems you have specified in your /etc/fstab, or, to mount file systems individually, use:
# mount /path # e.g.: mount /usr
Current Debian systems have mountpoints for removable media under /media, but keep compatibility symlinks in /. Create these as as needed, for example:
# cd /media # mkdir cdrom0 # ln -s cdrom0 cdrom # cd / # ln -s media/cdrom
You can mount the proc file system multiple times and to arbitrary locations, though /proc is customary. If you didn't use mount -a, be sure to mount proc before continuing:
# mount -t proc proc /proc
The command ls /proc should now show a non-empty directory. Should this fail, you may be able to mount proc from outside the chroot:
# mount -t proc proc /mnt/debinst/proc
Setting the third line of the file /etc/adjtime to “UTC” or “LOCAL” determines whether the system will interpret the hardware clock as being set to UTC respective local time. The following command allows you to set that.
# editor /etc/adjtime
Here is a sample:
0.0 0 0.0 0 UTC
The following command allows you to choose your timezone.
# dpkg-reconfigure tzdata
To configure networking, edit /etc/network/interfaces, /etc/resolv.conf, /etc/hostname and /etc/hosts.
# editor /etc/network/interfaces
Here are some simple examples from /usr/share/doc/ifupdown/examples:
###################################################################### # /etc/network/interfaces -- configuration file for ifup(8), ifdown(8) # See the interfaces(5) manpage for information on what options are # available. ###################################################################### # We always want the loopback interface. # auto lo iface lo inet loopback # To use dhcp: # # auto eth0 # iface eth0 inet dhcp # An example static IP setup: (broadcast and gateway are optional) # # auto eth0 # iface eth0 inet static # address 192.168.0.42 # network 192.168.0.0 # netmask 255.255.255.0 # broadcast 192.168.0.255 # gateway 192.168.0.1
Enter your nameserver(s) and search directives in /etc/resolv.conf:
# editor /etc/resolv.conf
A simple example /etc/resolv.conf:
search hqdom.local nameserver 10.1.1.36 nameserver 192.168.9.100
Enter your system's host name (2 to 63 characters):
# echo DebianHostName > /etc/hostname
And a basic /etc/hosts with IPv6 support:
127.0.0.1 localhost 127.0.1.1 DebianHostName # The following lines are desirable for IPv6 capable hosts ::1 ip6-localhost ip6-loopback fe00::0 ip6-localnet ff00::0 ip6-mcastprefix ff02::1 ip6-allnodes ff02::2 ip6-allrouters ff02::3 ip6-allhosts
If you have multiple network cards, you should arrange the names of driver modules in the /etc/modules file into the desired order. Then during boot, each card will be associated with the interface name (eth0, eth1, etc.) that you expect.
Debootstrap will have created a very basic /etc/apt/sources.list that will allow installing additional packages. However, you may want to add some additional sources, for example for source packages and security updates:
deb-src http://ftp.us.debian.org/debian jessie main deb http://security.debian.org/ jessie/updates main deb-src http://security.debian.org/ jessie/updates main
Make sure to run aptitude update after you have made changes to the sources list.
To configure your locale settings to use a language other than English, install the locales support package and configure it. Currently the use of UTF-8 locales is recommended.
# aptitude install locales # dpkg-reconfigure locales
To configure your keyboard (if needed):
# aptitude install console-setup # dpkg-reconfigure keyboard-configuration
Bemærk at tastaturet ikke kan angives mens i en chroot, men at det vil blive konfigureret i den næste genstart.
If you intend to boot this system, you probably want a Linux kernel and a boot loader. Identify available pre-packaged kernels with:
# apt-cache search linux-image
Installer så kernepakken efter dit valg via dets pakkenavn.
# aptitude install linux-image-arch-etc
To make your Debian GNU/Linux system bootable, set up your boot loader to load the installed kernel with your new root partition. Note that debootstrap does not install a boot loader, though you can use aptitude inside your Debian chroot to do so.
Check info grub or man lilo.conf for instructions on setting up the bootloader. If you are keeping the system you used to install Debian, just add an entry for the Debian install to your existing grub2 grub.cfg or lilo.conf. For lilo.conf, you could also copy it to the new system and edit it there. After you are done editing, call lilo (remember it will use lilo.conf relative to the system you call it from).
Installing and setting up grub2 is as easy as:
# aptitude install grub-pc
# grub-install /dev/sda
# update-grub
The second command will install grub2 (in this case in the MBR of sda). The last command will create a sane and working /boot/grub/grub.cfg.
Bemærk at dette antager at en /dev/sda-enhedsfil er blevet oprettet. Der er alternative metoder til at installere grub2, men de er uden for dette appendisk omfang.
Her er en grundlæggende /etc/lilo.conf som et eksempel:
boot=/dev/sda6root=/dev/sda6install=menu delay=20 lba32 image=/vmlinuz initrd=/initrd.img label=Debian
In case you can login to the system via console, you can skip this section. If the system should be accessible via the network later on, you need to install SSH and set up access.
# aptitude install ssh
Root login with password is disabled by default, so setting up access can be done by setting a password and re-enable root login with password:
# passwd # editor /etc/ssh/sshd_config
This is the option to be enabled:
PermitRootLogin yes
Access can also be set up by adding an ssh key to the root account:
# mkdir /root/.ssh # cat << EOF > /root/.ssh/authorized_keys ssh-rsa .... EOF
Lastly, access can be set up by adding a non-root user and setting a password:
# adduser joe # passwd joe
As mentioned earlier, the installed system will be very basic. If you would like to make the system a bit more mature, there is an easy method to install all packages with “standard” priority:
# tasksel install standard
Of course, you can also just use aptitude to install packages individually.
After the installation there will be a lot of downloaded packages in /var/cache/apt/archives/. You can free up some diskspace by running:
# aptitude clean
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| D.2. Diskpladskrævet for opgaver |  |
D.4. Installation af Debian GNU/Linux over Parallel Line IP (PLIP) |