Score:0

Ubuntu

Autoinstall support both EFI and Legacy boot

Utz

11/3/23, 2:03 PM

I'm trying to install Ubuntu 22.04 using Autoinstall. My generated ISO that includes userdata.yml (main autoinstall's file) has storage section, that should support both EFI and Legacy boot, but I cannot find a way to implement it.

Storage section in userdata.yml that supports only EFI boot:

  storage:
    config:
    - ptable: gpt
      path: /dev/sda
      wipe: superblock-recursive
      preserve: false
      name: ''
      grub_device: false
      type: disk
      id: disk-sda
    - device: disk-sda
      size: 1127219200
      wipe: superblock
      flag: boot
      number: 1
      preserve: false
      grub_device: true
      type: partition
      id: partition-0
    - fstype: fat32
      volume: partition-0
      preserve: false
      type: format
      id: format-0
    - device: disk-sda
      size: 1073741824
      wipe: superblock
      flag: ''
      number: 2
      preserve: false
      grub_device: false
      type: partition
      id: partition-1
    - fstype: ext4
      volume: partition-1
      preserve: false
      type: format
      id: format-1
    - device: disk-sda
      size: 54760833024
      wipe: superblock
      flag: ''
      number: 3
      preserve: false
      grub_device: false
      type: partition
      id: partition-2
    - name: myvg
      devices:
      - partition-2
      preserve: false
      type: lvm_volgroup
      id: lvm_volgroup-0
    - name: slashlv
      volgroup: lvm_volgroup-0
      size: 53687091200B
      wipe: superblock
      preserve: false
      type: lvm_partition
      id: lvm_partition-0
    - fstype: ext4
      volume: lvm_partition-0
      preserve: false
      type: format
      id: format-2
    - path: /
      device: format-2
      type: mount
      id: mount-2
    - path: /boot
      device: format-1
      type: mount
      id: mount-1
    - path: /boot/efi
      device: format-0
      type: mount
      id: mount-0

Storage section in userdata.yml that supports only Legacy boot:

  storage:
    config:
    - ptable: gpt
      path: /dev/sda
      wipe: superblock-recursive
      preserve: false
      name: ''
      grub_device: true
      type: disk
      id: disk-sda
    - device: disk-sda
      size: 1048576
      flag: bios_grub
      number: 1
      preserve: false
      grub_device: false
      type: partition
      id: partition-0
    - device: disk-sda
      size: 1073741824
      wipe: superblock
      flag: ''
      number: 2
      preserve: false
      grub_device: false
      type: partition
      id: partition-1
    - fstype: ext4
      volume: partition-1
      preserve: false
      type: format
      id: format-1
    - device: disk-sda
      size: 54760833024
      wipe: superblock
      flag: ''
      number: 3
      preserve: false
      grub_device: false
      type: partition
      id: partition-2
    - name: myvg
      devices:
      - partition-2
      preserve: false
      type: lvm_volgroup
      id: lvm_volgroup-0
    - name: slashlv
      volgroup: lvm_volgroup-0
      size: 53687091200B
      wipe: superblock
      preserve: false
      type: lvm_partition
      id: lvm_partition-0
    - fstype: ext4
      volume: lvm_partition-0
      preserve: false
      type: format
      id: format-2
    - path: /
      device: format-2
      type: mount
      id: mount-1
    - path: /boot
      device: format-1
      type: mount
      id: mount-0

My failure when I'm trying to install EFI with userdata.yml that supports only legacy boot (and the opposite) -

2022-11-03 09:48:37,448 ERROR root:39 finish: subiquity/Filesystem/apply_autoinstall_config: FAIL: autoinstall config did not create needed bootloader partition
2022-11-03 09:48:37,448 ERROR root:39 finish: subiquity/apply_autoinstall_config: FAIL: autoinstall config did not create needed bootloader partition

Again, I need to support both EFI and Legacy boot, in the same userdata.yml file.

Thanks!

976

2 + 2

uefi

grub-legacy

curtin

22.04

David

11/3/23, 2:08 PM

Am I misreading this you have the exact same info twice. From your question "Storage section in userdata.yml that supports only EFI boot:" this and the post after seems to be exactly the same .

Utz

11/3/23, 2:16 PM

I just wrote EFI twice, the yml is a bit different. Thanks!

Score:2

Ubuntu

Andrew Lowther

11/3/23, 11:02 PM

Officially, you can't create a single storage config that supports both BIOS and UEFI. The grub_device settings are incompatible. Quoting from one of the installer (subiquity) developers

Yes, probably. I actually wanted to clean this whole area up and make the config saner (for example, it really ought to be possible to install a system that will boot both legacy and UEFI) but it doesn’t look like I’m going to get around to that any time soon…

As a workaround, early-commands can be used to make a single config work. Here is a sample user-data snippet that I have used. It will modify the /autoinstall.yaml file depending on the existence of /sys/firmware/efi.

#cloud-config
autoinstall:
  storage:
    config:
    - type: disk
      match:
        size: largest
      ptable: gpt
      preserve: false
      name: ''
      grub_device: true
      id: disk-sda
    - type: partition
      device: disk-sda
      size: 4194304
      wipe: superblock
      flag: bios_grub
      number: 14
      preserve: false
      grub_device: false
      id: partition-14
    - type: partition
      device: disk-sda
      size: 111149056
      wipe: superblock
      flag: boot
      number: 15
      preserve: false
      grub_device: UEFI
      id: partition-15
    - type: partition
      device: disk-sda
      size: -1
      wipe: superblock
      number: 1
      preserve: false
      grub_device: false
      id: partition-1
    - type: format
      fstype: ext4
      volume: partition-1
      preserve: false
      id: format-1
    - type: mount
      path: /
      device: format-1
      id: mount-1
    - type: format
      fstype: fat32
      volume: partition-15
      preserve: false
      id: format-15
    - type: mount
      path: /boot/efi
      device: format-15
      id: mount-15
  early-commands:
    - |
      if [ -e "/sys/firmware/efi" ]; then
        sed -i -e "s/grub_device: UEFI/grub_device: true/" /autoinstall.yaml
      else
        sed -i -e "s/grub_device: UEFI/grub_device: false/" /autoinstall.yaml
      fi
      true

With this snippet all devices will end up with the same partition layout, which could be confusing. For example, a BIOS based machine will still end up with an unnecessary ESP partition mounted at /boot/efi, and a UEFI based machine will have an unnecessary bios_grub partition.

The cloud images have a partition layout that was used as inspiration for this config. The cloud images support both BIOS and UEFI and I wanted to duplicate that. The resulting partition table looks like this, where the final partition fills the disk.

Partition Table: gpt
Disk Flags:

Number  Start    End       Size      File system  Name  Flags
 1      1.00MiB  5.00MiB   4.00MiB                      bios_grub
 2      5.00MiB  111MiB    106MiB    fat32              boot, esp
 3      111MiB   20479MiB  20368MiB  ext4

+ 1

Utz

11/6/23, 8:02 AM

Can you please clarify in my example of `user-data` what should be added in the `early-commands` section? Thanks a lot!

Score:0

Ubuntu

Utz

11/6/23, 3:17 PM

Solution:

I deleted the whole storage section in user-data; The default autoinstall "knows" how to deal with it whether you are running in a UEFI system or a Legacy BIOS.

Note: It creates the following as default -

/boot - 2g
(If UEFI) /boot/efi - 1g±
/ - as LVM - 100g, or if your disk is less than 100g, it creates it with about 70% of the disk's size.
VG name - ubuntu-vg
LV name (that mounted to /) - ubuntu-lv

+ 1

Andrew Lowther

11/7/23, 10:54 PM

If you delete the whole `storage` config then the installer (subiquity) will use an `lvm` `layout` configuration [by default](https://github.com/canonical/subiquity/blob/c03b23d7e4aa66a25252a1de1578c5ab099f1667/subiquity/server/controllers/filesystem.py#L142).

Elon Musk

I sit in a Tesla and translated this thread with Ai:

EN: Autoinstall support both EFI and Legacy boot

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