A tape cartridge having dual cartridge memory modules to provide memory
redundancy, and a method and apparatus for providing redundancy of
cartridge memory information within a tape cartridge. The tape cartridge
comprises at least first and second cartridge memory modules, each of
which stores an identical set of critical information. Each of the first
and second cartridge memory modules includes enough critical information
to recover from a failure of either of the cartridge memory modules. The
method comprises the steps of providing at least two cartridge memory
modules in the tape cartridge, and storing an identical set of critical
information in each of the two cartridge memory modules. Each of the two
cartridge memory modules includes enough critical information to recover
from a failure of either cartridge memory module. In a preferred
embodiment, the CM modules are stacked one on top of another and increase
the amount of space available for tape directory storage.