B.5. Debian Partitioning Programs

Several varieties of partitioning programs have been adapted by Debian developers to work on various types of hard disks and computer architectures. Following is a list of the program(s) applicable for your architecture.

partman

Recommended partitioning tool in Debian. This Swiss army knife can also resize partitions, create filesystems and assign them to the mountpoints.

fdisk

The original Linux disk partitioner, good for gurus.

Be careful if you have existing FreeBSD partitions on your machine. The installation kernels include support for these partitions, but the way that fdisk represents them (or not) can make the device names differ. See the Linux+FreeBSD HOWTO

cfdisk

A simple-to-use, full-screen disk partitioner for the rest of us.

Note that cfdisk doesn't understand FreeBSD partitions at all, and, again, device names may differ as a result.

One of these programs will be run by default when you select Partition a Hard Disk. If the one which is run by default isn't the one you want, quit the partitioner, go to the shell (tty2) by pressing Alt and F2 keys together, and manually type in the name of the program you want to use (and arguments, if any). Then skip the Partition a Hard Disk step in debian-installer and continue to the next step.

If you will be working with more than 20 partitions on your ide disk, you will need to create devices for partitions 21 and beyond. The next step of initializing the partition will fail unless a proper device is present. As an example, here are commands you can use in tty2 or under Execute A Shell to add a device so the 21st partition can be initialized:

# cd /dev
# mknod hda21 b 3 21
# chgrp disk hda21
# chmod 660 hda21

Booting into the new system will fail unless proper devices are present on the target system. After installing the kernel and modules, execute:

# cd /target/dev
# mknod hda21 b 3 21
# chgrp disk hda21
# chmod 660 hda21

B.5.1. Partitioning for Alpha

Booting Debian from the SRM console (the only disk boot method supported by sarge) requires you to have a BSD disk label, not a DOS partition table, on your boot disk. (Remember, the SRM boot block is incompatible with MS-DOS partition tables — see Section 5.1.1, “Alpha Console Firmware”.) As a result, partman creates BSD disk labels when running on alpha, but if your disk has an existing DOS partition table the existing partitions will need to be deleted before partman can convert it to use a disk label.

If you have chosen to use fdisk to partition your disk, and the disk that you have selected for partitioning does not already contain a BSD disk label, you must use the “b” command to enter disk label mode.

Unless you wish to use the disk you are partitioning from Tru64 Unix or one of the free 4.4BSD-Lite derived operating systems (FreeBSD, OpenBSD, or NetBSD), it is suggested that you do not make the third partition contain the whole disk. This is not required by aboot, and in fact, it may lead to confusion since the swriteboot utility used to install aboot in the boot sector will complain about a partition overlapping with the boot block.

Also, because aboot is written to the first few sectors of the disk (currently it occupies about 70 kilobytes, or 150 sectors), you must leave enough empty space at the beginning of the disk for it. In the past, it was suggested that you make a small partition at the beginning of the disk, to be left unformatted. For the same reason mentioned above, we now suggest that you do not do this on disks that will only be used by GNU/Linux. When using partman, a small partition will still be created for aboot for convenience reasons.