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.

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

See the mac-fdisk manual page for information on how to create partitions. One key point, is that the swap partition is identified on Mac type disks by its name; it must be named `swap'. All Mac linux partitions are the same partition type, Apple_UNIX_SRV2. Please read the fine manual. We also suggest reading the mac-fdisk Tutorial, which includes steps you should take if you are sharing your disk with MacOS.