PartMan

Basic Info

Partman is an incomprehensible automatic partitioning language.

Help Files

These files are in the Debian and Ubuntu packages, and give some explanation

PartManAuto

PartManAutoRaid

Dissecting a Semi-working configuration

# Automatic software RAID 1 with LVM partitioning

d-i     partman-auto/method     string  raid

This sentence makes partman know that it will be making a raid

# Use the first two disks
d-i     partman-auto/disk       string  /dev/sda /dev/sdb

after d-i partman-auto/disk you must put the list of hard drives that are going to be used

# Define physical partitions
d-i     partman-auto/expert_recipe      string  \
                multiraid ::                                                    \
                        400000    1000    9500000       raid                    \
                                $primary{ }  method{ raid }                     \
                        .                                                       \

                        4000    1200    4100    linux-swap                      \
                        $primary{ } method{ swap } format{ }                    \
                        .

An interesting thing about partman is that you can put everything on one line, or you can break lines using the character "\". Use a "." in between hard drives. $primary{ } is needed to make the partition a primary partition. method { } is used to tell it what type to format. You can use swap, raid, or format. format { } tells partman to format the partition. Don't put this statement in a section that you will be using for the raid. use_filesystem{ } makes partman use a file system (don't know why this isn't done by the filesystem command) filesystem{ X } use ext3, murderfs, xfs, etc in here to tell it what filesystem to run mountpoint{ X } use things like /, /mnt/sda3, etc

# Parameters are:
# <raidtype> <devcount> <sparecount> <fstype> <mountpoint> \
#          <devices> <sparedevices>
d-i     partman-auto-raid/recipe        string  \
                1       2       0       ext3    /                       \
                        /dev/sda1#/dev/sdb1                             \
                .

This snippet is telling us to make a raid 1, with 2 devices, 0 spares, ext3 filesystem, mounted at /, and across /dev/sda1 and /dev/sda2

d-i     partman-md/confirm              boolean true

Theoretically now it confirms stuff automatically. It doesn't. Partman lies

d-i     partman-md/device_remove_md     boolean true

This lets partman remove any existing raids

d-i     partman/confirm_write_new_label boolean true
d-i     partman/choose_partition        select  finish
d-i     partman/confirm                 boolean true

d-i     partman-lvm/device_remove_lvm   boolean true

d-i     mdadm/boot_degraded             boolean true

Most of these possibly do what they appear to do.

Boot degraded is important - if we have a disk failure we'd still like the system to boot, just warn us.