-Digidesign does not qualify any one style of file back up.* CD-R, DVD-RAM, and Tape Backup are just a few of the options.-CD-R's are probably the most common method, however will only store approximately 650-700mgs. Some are re-recordable.-DVD-RAM's can hold up to 5.2 gigs and are re-recordable.-Tape Backup systems (various types) are capable of storing 40+ gigs and are re-recordable.-You should never back up your audio in "Compression" mode. Use a "Native" mode.-Any system that can backup/restore SDII or other compatible files will work.-Check with manufacturers regarding their systems for capacity and other specifications.*Back up & restoration software & hardware will vary in their features, specifications, and results depending upon their speed, capacity, and error checking/correction capabilities.