# disk mapping. In this mapping each CHANNEL is represented by
# the letters a-z, and the RANK is represented by the numbers
# 1-n. A CHANNEL should identify a group of RANKS which are all
# disk mapping. In this mapping each CHANNEL is represented by
# the letters a-z, and the RANK is represented by the numbers
# 1-n. A CHANNEL should identify a group of RANKS which are all