A magazine-based data storage library is described that essentially provides a first tape cartridge adapted to retain first data and first metadata, a second tape cartridge adapted to retain second data and second metadata, a random access storage memory, such as a hard disk drive, whereon parity of the first data and the second data along with the first metadata and second metadata is retained. It is not required that the first data and the second data be written in parallel. The parity data on the random access storage memory is transferred to a parity tape, which can be used to reconstruct any data lost from either the first tape cartridge or the second tape cartridge.