Comment 4 for bug 1799488

In the same env I can create centos and boot success.
export DIB_BLOCK_DEVICE_CONFIG='
- local_loop:
    name: image0

- partitioning:
    base: image0
    label: mbr
    partitions:
      - name: root
        flags: [ boot,primary ]
        size: 100%

- lvm:
    name: lvm
    base: [root]
    pvs:
      - name: pv
        options: ["--force"]
        base: root

    vgs:
      - name: vg
        base: ["pv"]
        options: ["--force"]

    lvs:
      - name: lv_root
        base: vg
        size: 1800M

      - name: lv_home
        base: vg
        size: 200M

- mkfs:
    name: fs_root
    base: lv_root
    label: "img-rootfs"
    type: "ext4"
    mount:
      mount_point: /
      fstab:
          options: "rw,relatime"
          fsck-passno: 1

- mkfs:
    name: fs_home
    base: lv_home
    type: "ext4"
    mount:
      mount_point: /home
      fstab:
          options: "rw,nodev,relatime"
'

/root/ironic/dib_new/bin/disk-image-create centos7 vm devuser disable-selinux dhcp-all-interfaces dracut-regenerate -o centos7.3