LTFS (Linear Tape File System) shows each each "file" as often a pretty dumb "write-only" mechanism / append-only file system. That is: if a file A is modified

LTFS (Linear Tape File System) shows each each "file" as often a pretty dumb "write-only" mechanism / append-only file system. That is: if a file A is modified, LTFS "represents" this by marking fileA as dead, then copying most of the contents of A to the end of the tape... with the few modifications in the correct location. Because tapes have so much capacity, this ends up working much better in practice than you'd expect. Especially if your backup-like software (or Apache-log files or whatever you're archiving) are largely append-only (ex: Wikipedia dumps or whatever huge data-storage requirements you're doing). ----------- Allegedly anyway, I don't really use tapes myself, but I amuse myself by looking at their specs / usability every now and then. It seems like the details of LTFS depend on each manufacturer's system, but it seems like LTFS itself is somewhat cross-compatible. Some LTFS-library docs suggest that different tapes are different folders. Others suggest that different tapes are mount/unmounted (which sends a sequence of commands to the little tape-robot to fetch the correct tape, which it does so by scanning barcodes or maybe going to correct slot) ----------- Tapes are meant to be used in a "jukebox-style" application IMO. If you need just one tape, you're doing it wrong. If you need 80-tapes, then doing it manually is obviously wrong, you should pay a bit extra for that "jukebox / tape-library" robot to fetch the right tapes automatically. > Does it already exist as open-source? Red Hat claims LTFS support. But I imagine this is only "disk-level LTFS", and not "library / robot LTFS".