David - The Admin Ref manual description of the Physical and Logical Space report element from Query OCCupancy is superficial, leading the customer to believe that the Logical value is just the amount of space occupied by client files. According to info I've seen, logical space also includes headers housing control information for each file, such as magic numbers, CRC info, segment numbering, server ID, etc. The size of the header info can vary as TSM evolves, and so may differ across TSM releases. The header size can be seen in the output of the SHow INVObject command for a given ObjectID.
Richard Sims http://people.bu.edu/rbs
