Some suggestions:

  - allow multiple sort orders of LUNs, may be useful if there are a

    lot of LUNs [20130507]

  - add unit option for different size representations [proposed by

    Pascal Gregis 20121019]

    - done: -s: SI units for bytes; -ss: IEC 80000-3 prefixes for bytes

      (e.g. 3.56GiB); -sss: size as logical block count, exact in decimal