There are many wishlist features that we might desire from any installer of GNU/Linux and that are related to partitioning:
The partitioner should support different file systems. Some of them need more care than only libraries and suitable arguments for mount.
It should support not only regular partitions but also software RAID and LVM as well as encrypted file systems.
It should be able to partition disks automatically and allow the user to inspect and customise the automatic partitioning later.
It should be able to resize partitions and move their contents from one place to another.
The users should be protected from mistakes – by allowing them to undo their partitioning operations.
The partitioner should discover that there is already some installed GNU/Linux system and analyse its fstab, passwd, etc. in order to provide an automatic upgrade from the old already installed GNU/Linux system to the new one.
One nice feature of the Debian installer is that it is modular. Its components are packaged in separate udebs and they can have relatively independent development process. This document describes how we can solve all mentioned tasks keeping the Debian installer as modular as it is now. Ideally in order to add some new feature only a few new udebs must be all that is needed – no changes in the existing udebs and no recompilation would be required.
The script partman from the package partman-base opens the main partitioning menu; it
may look like this one:
+------------------+ [!!] Partition the storage devices +-----------------+ | Partition, free space or device to be modified | | | | IDE1 master - Seagate U Series 40810 (40.0 GB) | | #3 primary 2.1 GB B F ext3 / | | pri/log 4.4 GB FREE SPACE | | #5 logical 3.6 GB | | #7 logical 10.0 GB F ext3 /usr | | #8 logical 19.9 GB K ext2 /home | | IDE2 master - Maxtor 6Y120L0 (122.9 GB) | | #7 logical 1.0 GB linux-swap | | logical 114.5 GB FREE SPACE | | #5 logical 5.5 GB reiserfs | | #6 logical 1.9 GB | | | | Undo changes to partitions | | Finish partitioning and write changes to disk | | | | <Go Back> <Continue> | | | +-------------------------------------------------------------------------+
When the users choose some free space they are offered to create a new partition just like they are in cfdisk. When users choose a partition they are offered with a menu with various editing operations:
+------------------+ [!!] Partition the storage devices +-----------------+ | Settings on the partition: | | | | Usage method: format the partition | | File system: ext3 | | Mount point: /var/mail | | Mount options: noatime,nodev,nosuid,noexec,usrquota | | Bootable flag: off | | Size: 995.2 MB | | | | Finished setting up partition | | Delete the partition | | | | <Go Back> <Continue> | | | +-------------------------------------------------------------------------+
All udebs are allowed to add items to this menu as well as to several other
menus. They can add new items in the list of devices such as software RAID and
LVM devices, networked file systems, encrypted partitions, etc. The package
partman-partitioning is responsible for
pure partitioning operations such as creation of new partitions and deletion.
The packages partman-target and
partman-basicmethods are responsible
for the items `Choose how this partition should be used' and `Choose a file
system'. The package partman-basicfilesystems adds support for
ext2, linux-swap,
fat16 and fat32. The package partman-ext3 adds support for
ext3.