Comment 2 for bug 1488632

OK, I can reproduce in a trusty vm curtin/launch and this config:

% cat partprobe.yml
early_commands:
  add_repo: ["add-apt-repository", "-y", "ppa:maas-maintainers/experimental"]

partitioning_commands:
    builtin:
    - curtin
    - block-meta
    - custom
storage:
    config:
    - grub_device: true
        id: sda
        model: TOSHIBA THNSNH12
        name: sda
        ptable: msdos
        path: /dev/vdc
        type: disk
        wipe: superblock
    - device: sda
        id: sda-part1
        name: sda-part1
        number: 1
        offset: 2097152B
        size: 128032530432B
        type: partition
        uuid: 19a4ba9c-f70a-4826-bd7c-5639476f7120
        wipe: superblock
    - devices:
        - sda-part1
        id: vgroot
        name: vgroot
        type: lvm_volgroup
        uuid: 884d7eb2-1e72-4807-8ed7-70465626bf1f
    - id: vgroot-lvroot
        name: lvroot
        size: 128031129600B
        type: lvm_partition
        volgroup: vgroot
    - fstype: ext4
        id: vgroot-lvroot_format
        label: root
        type: format
        uuid: a83e1778-f7c7-485a-b2b8-eabce888d4e1
        volume: vgroot-lvroot
    - device: vgroot-lvroot_format
        id: vgroot-lvroot_mount
        path: /
        type: mount
    version: 1

% ./tools/launch -n user,mac=c0:d6:9f:2c:e8:80 -d test1.img:128G ~/download/trusty-server-cloudimg-amd64-disk1.qcow2 -- curtin install --config=partprobe.yml cp:///