CoreOS is not able to handle MBR disks?

I’ve defined a disk like that and do not want it to be wiped/the partition table to be recreated – I just want to use and mount it:

variant: fcos
version: 1.3.0
storage:
  disks:
    - device: /dev/disk/by-id/usb-[…]:0
      wipe_table: false
      partitions:
      - size_mib: 0
        start_mib: 0
        label: external

As I had to discover it seems to be somewhat of an oldish disk, which is still MBR-partitioned (Gparted shows this as msdos).

When the Ignition file runs, however, the log tells me one error:

“/dev/disk/by-id/usb-[…]:0” is not a gpt disk

Okay so? In the current Butane spec I also did not find any way to specify that it is a MBR disk, so… uhm… can CoreOS support such a legacy stuff?

Otherwise, the only other way forward for me would be to try the potentially destructive idea of converting the disk from MBR to GPT

Ignition doesn’t support partitioning MBR-only disks. However, if you don’t want to partition the disk and just want to mount the filesystems on it, you can omit it from the storage.disks section and the partitioning code will ignore it. The important part for mounting is a storage.filesystems section with with_mount_unit: true.

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