Comment 1 for bug 1687729

The "Installation" tab/log on the web UI shows this:

curtin: Installation started. (0.1.0~bzr480-0ubuntu1~ubuntu16.04.1)
blockdev: ioctl error on BLKRRPART: Device or resource busy
Creating new GPT entries.
Warning: The kernel is still using the old partition table.
The new table will be used at the next reboot or after you
run partprobe(8) or kpartx(8)
The operation has completed successfully.
blockdev: ioctl error on BLKRRPART: Device or resource busy
/dev/sda missing partitions: 15
Unexpected error while running command.
Command: ['partition', '--format=uefi', '/dev/sda']
Exit code: 1
Reason: -
Stdout: ''
Stderr: ''
curtin: Installation failed with exception: Unexpected error while running command.
Command: ['curtin', 'block-meta', 'simple']
Exit code: 3
Reason: -
Stdout: blockdev: ioctl error on BLKRRPART: Device or resource busy
        Creating new GPT entries.
        Warning: The kernel is still using the old partition table.
        The new table will be used at the next reboot or after you
        run partprobe(8) or kpartx(8)
        The operation has completed successfully.
        blockdev: ioctl error on BLKRRPART: Device or resource busy
        /dev/sda missing partitions: 15
        Unexpected error while running command.
        Command: ['partition', '--format=uefi', '/dev/sda']
        Exit code: 1
        Reason: -
        Stdout: ''