def calc_raid_partition_sectors(psize, start):
    """Calculates end sector and converts start and end sectors including

    the unit of measure, compatible with parted.
    :param psize: size of the raid partition
    :param start: start sector of the raid partion in integer format
    :return: start and end sector in parted compatible format, end sector
        as integer
    """

    if isinstance(start, int):
        start_str = '%dGiB' % start
    else:
        start_str = start

    if psize == -1:
        end_str = '-1'
        end = '-1'
    else:
        if isinstance(start, int):
            end = start + psize
        else:
            # First partition case, start is sth like 2048s
            end = psize
        end_str = '%dGiB' % end

    return start_str, end_str, end