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[ Anmerkung: Diese Anleitung zu fdisk ist ein Auszug eines News- ]
[ Artikels von Matt Welsh, den wir um einige Kommentare ]
[ ergΣnzt haben. ]
---------------------------------------------------------------------
The Linux Installation HOWTO
by Matt Welsh, mdw@sunsite.unc.edu
v2.1, 23 March 1994
4.1. Repartitioning
On most systems, the hard drive is already dedicated to partitions for
MS-DOS, OS/2, and so on. You need to resize these partitions in order
to make space for Linux.
A partition is just a section of the hard drive set aside for a
particular operating system to use. If you only have MS-DOS installed,
your hard drive probably has just one partition, entirely for MS-DOS.
To use Linux, however, you'll need to repartition the drive, so that
you have one partition for MS-DOS, and one (or more) for Linux.
The problem with resizing partitions is that there is no way to do it
(easily) without deleting the data on those partitions. Therefore,
you will need to make a full backup of your system before
repartitioning. In order to resize a partition, we simply delete the
partition(s), and re-create them with smaller sizes.
NOTE: There is a non-destructive disk repartitioner available for MS-
DOS, called FIPS. Look on sunsite.unc.edu in the directory
/pub/Linux/system/Install. With FIPS, a disk optimizer (such as Norton
Disk Doctor), and a little bit of luck, you should be able to resize
MS-DOS partitions without destroying the data on them.
[Anm: Wir halten FIPS fⁿr noch nicht ausgereift genug, um als ]
[ Standardl÷sung in einer Disrtribution angeboten zu werden. ]
If you're not using FIPS, however, the classic way to modify
partitions is with the program FDISK. For example, let's say that you
have an 80 meg hard drive, dedicated to MS-DOS. You'd like to split it
in half---40 megs for MS-DOS and 40 megs for Linux. In order to do
this, you need to run FDISK under MS-DOS, delete the 80 meg MS-DOS
partition, and re-create a 40 meg MS-DOS partition in its place. You
can then format the new partition and reinstall your MS-DOS software
from backups.
Use of MS-DOS FDISK should be self-explanatory. You'll need to make a
full backup of your system, and have a bootable MS-DOS floppy with
utilities such as FDISK.EXE and FORMAT.COM installed (the original MS-
DOS installation disks are the best thing to use for this). Booting
from the floppy, you run FDISK on your hard drive, and use the menu
options to delete your current MS-DOS partition, and then re-create it
with a smaller size. You can then re-install the MS-DOS software from
backup.
The mechanism used to repartition for OS/2 and other operating systems
is similar. See the documentation for those operating systems for
details.
4.2.1. Using fdisk
To create partitions, you'll use the Linux fdisk program. After
logging in as root, run the command
fdisk <drive>
[ Anm: fdisk wird automatisch vom Installationsskript aufgerufen, wenn Sie ]
[ im Hauptmenⁿ den Punkt "a" wΣhlen. Sie mⁿssen dann nur noch die ]
[ entsprechende Festplatte angeben. ]
where <drive> is the name of the drive that you wish to create Linux
partitions on. Hard drive device names are:
o /dev/hda First IDE drive
o /dev/hdb Second IDE drive
o /dev/sda First SCSI drive
o /dev/sdb Second SCSI drive
and so on. For example, to create Linux partitions on the first
SCSI drive in your system, use the command
fdisk /dev/sda
If you use fdisk without an argument, it will assume /dev/hda.
Use of fdisk is simple. The command ``p'' displays your current
partition table. ``n'' creates a new partition, and ``d'' deletes a
partition.
To Linux, partitions are given a name based on the drive which they
belong to. For example, the first partition on /dev/hda is /dev/hda1,
the second is /dev/hda2, and so on.
NOTE: You should not create or delete partitions for operating systems
other than Linux with Linux fdisk. That is, don't create or delete MS-
DOS partitions with this version of fdisk; use MS-DOS's version of
FDISK instead. If you try to create MS-DOS partitions with Linux
fdisk, chances are MS-DOS will not recognize the partition and not
boot correctly.
Here's an example of using fdisk. Here, we have a single MS-DOS
partition using 61693 blocks on the drive, and the rest of the drive
is free for Linux. (Under Linux, one block is 1024 bytes. Therefore,
61693 blocks is about 61 megabytes.) We will create two Linux
partitions: one for swap, and one for the root filesystem.
First, we use the ``p'' command to display the current partition
table. As you can see, /dev/hda1 (the first partition on /dev/hda) is
a DOS partition of 61693 blocks.
______________________________________________________________________
Command (m for help): p
Disk /dev/hda: 16 heads, 38 sectors, 683 cylinders
Units = cylinders of 608 * 512 bytes
Device Boot Begin Start End Blocks Id System
/dev/hda1 * 1 1 203 61693 6 DOS 16-bit >=32M
Command (m for help):
______________________________________________________________________
Next, we use the ``n'' command to create a new partition. The Linux
root partition will be 80 megs in size.
______________________________________________________________________
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
______________________________________________________________________
A primary partition is simply one of the 4 partitions on your drive.
An extended partition allows you to create multiple logical partitions
within it; this allows you to go over the four-partition limit on the
drive. In most cases, you should only use primary partitions unless
you need more than 4 partitions on a drive.
______________________________________________________________________
Partition number (1-4): 2
First cylinder (204-683): 204
Last cylinder or +size or +sizeM or +sizeK (204-683): +80M
______________________________________________________________________
The first cylinder should be the cylinder AFTER where the last
partition left off. In this case, /dev/hda1 ended on cylinder 203, so
we start the new partition at cylinder 204.
As you can see, if we use the notation ``+80M'', it specifies a
partition of 80 megs in size. Likewise, the notation ``+80K'' would
specify an 80 kilobyte partition, and ``+80'' would specify just an 80
byte partition.
______________________________________________________________________
Warning: Linux cannot currently use 33090 sectors of this partition
______________________________________________________________________
If you see this warning, you can ignore it. It is left over from an
old restriction that Linux filesystems could only be 64 megs in size.
However, with newer filesystem types, that is no longer the case...
partitions can now be up to 4 terabytes in size.
Next, we create our 10 megabyte swap partition, /dev/hda3.
______________________________________________________________________
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 3
First cylinder (474-683): 474
Last cylinder or +size or +sizeM or +sizeK (474-683): +10M
______________________________________________________________________
Again, we display the contents of the partition table. Be sure to
write down the information here, especially the size of each partition
in blocks. You need this information later.
______________________________________________________________________
Command (m for help): p
Disk /dev/hda: 16 heads, 38 sectors, 683 cylinders
Units = cylinders of 608 * 512 bytes
Device Boot Begin Start End Blocks Id System
/dev/hda1 * 1 1 203 61693 6 DOS 16-bit >=32M
/dev/hda2 204 204 473 82080 83 Linux native
/dev/hda3 474 474 507 10336 83 Linux native
______________________________________________________________________
Note that the Linux swap partition (here, /dev/hda3) has type ``Linux
native''. We need to change the type of the swap partition to ``Linux
swap'' so that the installation program will recognize it as a swap
partition. In order to do this, use the fdisk ``t'' command:
______________________________________________________________________
Command (m for help): t
Partition number (1-4): 3
Hex code (type L to list codes): 82
______________________________________________________________________
If you use ``L'' to list the type codes, you'll find that 82 is the
code corresponding to Linux swap.
To quit fdisk and save the changes to the partition table, use the
``w'' command. To quit fdisk WITHOUT saving changes, use the ``q''
command.
After quitting fdisk, the system may tell you to reboot to make sure
that the changes took effect. In general there is no reason to reboot
after using fdisk---the version of fdisk on the Slackware distribution
is smart enough to update the partitions without rebooting.
[ Anm: Unser fdisk auch... Aber wir empfehlen trotzdem den reboot... ]