Compressing data with DUMP
 

How can I compress the data when using the program DUMP? I know there is a "-j" option with levels 0-9, but what level is the highest compressed and what is the lowest? Do you have any additional ideas for me? I'm trying to use DDS-125 mm tapes and it seems like when I'm backing up to it, it only stores up to 1GB and then I have to put a new tape in. Thanks.