Using d-i partman recipe strings?

Question

I want to automatically partition all of my workstations in the same way:

First partition is a bootable 1GB ext4 /boot partition
Second partition is a 2GB swap partition
Third partition is an ext4 / partition that takes up whatever is left
All partitions should be formatted

I think adding this to my preseed.cfg will accomplish what I want:

d-i partman-auto/workstation_recipe string \
    root :: \
        1024 1023 1024 ext4 \
            $primary{ } $bootable{ } \
            method{ format } format{ } \
            use_filesystem{ } filesystem{ ext4 } \
            mountpoint{ /boot } \
        . \
        2048 2047 2048 linux-swap \
            $primary{ } \
            method{ swap } format{ } \
        . \
        17408 100000000000 -1 ext4 \
            $primary{ } \
            method{ format } format{ } \
            use_filesystem{ } filesystem{ ext4 } \
            mountpoint{ / } \
        .

This is based on this blog. Will this do what I want, and is there anything else I need to add to my preseed.cfg to make it accept these instructions without user intervention? I have never used partman recipes before.

score 10 · Accepted Answer · answered Feb 07 '17 at 20:30

I figured this out after spending days scouring the internet for any shred of information about partman - it is not very well-documented at all. Here's the config I used:

# This automatically creates a standard unencrypted partitioning scheme.
d-i partman-auto/disk string /dev/sda
d-i partman-auto/method string regular
d-i partman-lvm/device_remove_lvm boolean true
d-i partman-md/device_remove_md boolean true
d-i partman-lvm/confirm boolean true
d-i partman-lvm/confirm_nooverwrite boolean true
d-i partman-auto/choose_recipe select unencrypted-install
d-i partman-auto/expert_recipe string \
        unencrypted-install :: \
                1024 1024 1024 ext4 \
                        $primary{ } $bootable{ } \
                        method{ format } format{ } \
                        use_filesystem{ } filesystem{ ext4 } \
                        mountpoint{ /boot } \
                . \
                2048 2048 2048 linux-swap \
                        $primary{ } \
                        method{ swap } format{ } \
                . \
                17408 100000000000 -1 ext4 \
                        $primary{ } \
                        method{ format } format{ } \
                        use_filesystem{ } filesystem{ ext4 } \
                        mountpoint{ / } \
                .
d-i partman-md/confirm boolean true
d-i partman-partitioning/confirm_write_new_label boolean true
d-i partman/choose_partition select finish
d-i partman/confirm boolean true
d-i partman/confirm_nooverwrite boolean true

Just drop that in your preseed and you should be good to go. Line by line:

Use disk /dev/sda
Do a regular install (not encrypted or LVM)
Remove any existing LVM without prompting
Remove any existing RAID setup without prompting
Confirm that this is what you want
Confirm again
Select the "unencrypted-install" recipe, which is specified below
This is a single logical line that specifies the entire recipe, one partition at a time. It creates the partition table exactly as I specified in the question.
Confirm again
Allow partman to write new labels
Finish the process
Confirm again
Confirm again

And there you go, works perfect.

Well done for posting what you found. The paucity of info and lack of exhaustive directory for all the preseed directives is a travesty of modern computing. I dread to think of `$myTimeWasted*$numEngineers`. — volvox, May 22 '20 at 18:59
Can you explain why did you choose 17408 for the minimum size? It seems a number that you calculated carefully ... this is what I'm trying to understand .. if you are about to make minimum of 17GB, why not go with 17000 ? How did you get that 17408 ? — MaXi32, Apr 09 '21 at 02:07
@MaXi32 OP is consistently using power of two sizing. First partition is 1GiB second is 2GiB and third at least 17GiB — JJ Roman, Dec 23 '21 at 22:16
What is the number of `n` that you are getting `17,408`? The first is correct where `2^n = (2^10) =1024`, The second one is also correct `2^11 = 2048`, The third is not in the chart of power 2 sizings, the minimum size would be `2^14` which is equal to `16,384`. So `17,408` is not in that range. If you pick `2^15` it is equal to `32,768` . So, I guess he picked a random number without thinking. Still does not answer my question. — MaXi32, Dec 23 '21 at 22:53
Actually, I just got the answer myself, The number he picked is actually just a random number where most people will do this without reason. When he put `-1` in the last partition (the third argument), it is already assumed that the last partition would take the rest of the available space so this line: `17408 100000000000 -1 ext4` where the number `17408` and `100000000000` are not important to have bigger value. — MaXi32, Dec 23 '21 at 23:05

score 2 · Answer 2 · answered Nov 16 '19 at 23:15

I know that this is an old post but I am not sure if hard coding /dev/sda is a good idea. Instead, I'd use something similar to

d-i partman/early_command string \
    USBDEV=$(list-devices usb-partition | sed "s/\(.*\)./\1/");\
    if [ ! -z "$USBDEV" ]; then \
        BOOTDEV=$(list-devices disk | grep -v "$USBDEV" | head -1);\
    else \
        BOOTDEV=$(list-devices disk | head -1);\
    fi; \
    debconf-set partman-auto/disk $BOOTDEV;\
    debconf-set grub-installer/bootdev $BOOTDEV;\
    lvremove --select all -ff -y; vgremove --select all -ff -y; pvremove ${BOOTDEV}* -ff -y

To make sure that the first internal drive is used as the installation medium and any possible external usb drive is excluded as the enumeration order might change dynamically.

score 1 · Answer 3 · answered Feb 06 '17 at 23:18

1

Try these 3 lines (making changes as fits):

d-i partman-auto/disk string /dev/sda
d-i partman/choose_partition select finish
d-i partman/confirm boolean true

answered Feb 06 '17 at 23:18

tshepang

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Hi @Tshepang, thank you for your answer. This was the start of what I needed to do. These lines will select /dev/sda for partitioning and get you ready to partition that disk. Setting up the partman recipe was a much more involved process, but I managed to do it; see my answer below. – user5104897 Feb 07 '17 at 21:00

Using d-i partman recipe strings?

3 Answers3