Comment 3 for bug 1513009

I believe by default, maas 1.9 now uses LVM, which probably means that this check in ceph/charmhelpers is no longer sufficient (as the device is no longer mounted, the LV ends up getting mounted):

    if not os.path.exists(dev):
        log('Path {} does not exist - bailing'.format(dev))
        return

    if not is_block_device(dev):
        log('Path {} is not a block device - bailing'.format(dev))
        return

    if (is_osd_disk(dev) and not reformat_osd):
        log('Looks like {} is already an OSD, skipping.'.format(dev))
        return

    if is_device_mounted(dev):
        log('Looks like {} is in use, skipping.'.format(dev))
        return