Ubuntu autoinstall failing when creating partitions

I have a problem with autoinstall. The config loads correctly, but when trying to create the partitions it fails. I'm running everything in a virtual machine before testing it on the live system.

My config looks like this:

#cloud-config
autoinstall:
  version: 1
  identity:
    hostname: <redacted>
    password: "<redacted>"
    username: <redacted>
  locale: <redacted>
  keyboard:
    layout: <redacted>
  ssh:
    install-server: true
    authorized-keys:
      - "<redacted>"
    allow-pw: false
  drivers:
    install: true
  timezone: <redacted>
  storage:
    swap:
      size: 0
    config:
      - type: disk
        match: 
          size: smallest
        id: hdd0
        ptable: gpt
        grub_device: true
      - type: partition
        number: 1
        id: boot-part
        device: hdd0
        size: 2G
        flag: boot
      - type: partition
        number: 2
        id: root-part
        device: hdd0
        size: -1
      - type: format
        id: boot-format
        volume: boot-part
        fstype: ext4
        label: BOOT
      - type: format
        id: root-format
        volume: root-part
        fstype: ext4
        label: ROOT
      - type: mount
        id: root-mount
        device: root-format
        path: /
      - type: mount
        id: boot-mount
        device: boot-format
        path: /boot
      - type: disk
        match: 
          size: largest
        id: hdd1
        ptable: gpt
      - type: partition
        number: 1
        id: storage-part
        device: hdd1
        size: 100%
      - type: format
        id: storage-format
        volume: storage-part
        fstype: ext4
        label: STORAGE
      - type: mount
        id: storage-mount
        device: storage-format
        path: /mnt/storage

Here's a screenshot from the crash dump (since I can't copy text from my VM).

Why do sgdisk fail with the message "Could not create partition 1 from 2048 to 4196351"? Is my config bad, or what's causing it to misbehave?

as I understand the Autoinstall Docs, you should set the size to -1 instead of 100% if you want the partition to fill up the rest of the disk. You did that in the root disk properly, but not in the storage-part Partition

But the error itself looks like your HHD0 is not even 2GB in Size.

Also, you normally have a bios_grub Partition of 1M before your Boot Partition.