DH> I can easily backup the 75 Meg onto one DC600 cartridge (in QIC 120
DH> format). The same 75 Meg requires 4 cartridges when I use rdump to
DH> backup across the network.
If you backup on a local tape, the tape will most likely be operated in the
"streaming mode", where there is little or no stop-and-go. When operated via
network, the tape data rate might be about as high as the network data rate
(measured with ftp on an idle 4Mbit token ring). So the tape operates in
stop-and-go mode, significantly reducing its capacity. In the manual of the
tape, there is a picture saying the capacity is reduced from 150 MB to 30 MB
when operated in non-streaming mode. I personally have trouble believing this
relation, especially at large block sizes, but its given in IBM's docs...