| Term | Explanation |
|---|---|
| ACL | Access list of the server: which API key may use which directories |
| Application-consistent | Applications have written back their buffers; achieved with hooks or VSS writers |
| Archive | a run as a single file (.cba), readable without a store |
| Bit rot | creeping data damage on the storage medium; scrub finds it |
| Channel | separate update stream (e.g. alpha) with its own manifest |
| Chunk | piece of the source cut by content, unit of deduplication |
| Crash-consistent | State as after a power failure; journaling file systems and databases with a log cope with it |
| Deduplication | the same data is stored only once, recognized by the ID (content hash) |
| FastCDC | Method that sets chunk boundaries by content, so that insertions do not shift the following chunks |
| Garbage collection | Part of prune/delete: removes data no run needs any more |
| Generation | independent store <store>.g<date>.cbs that shares no data with older ones |
| Hold | held backup: the process ends, the run continues later at the same place (bkp_sched hold, maintenance mode of the target); different from a pause |
| ID | Content hash of an object (sha256, blake3 or xxh3-128), formed with a key when encrypted |
| Pack | File in the store with many objects (about 64 MiB) |
| Pause | interrupted run (bkp_sched pause, Ctrl+P, bkp_target --sched-pause): the process stays active and waits for “Resume” or the end of --for; a backup paused longer than pause-max is held by the scheduler |
| Pinning | the client only accepts a certain certificate instead of any certificate authorities |
| Replay | renewed delivery of an old, validly signed manifest; prevented by expiry date and increasing number |
| Run | a backup in the store; can be restored on its own |
| Sink | a target store of a run (local or on a server) |
| Site server | bkp_sitesrv: reconciles what the machines of an account share with each other (own targets, released schedulers); hosted, in your own network or at the partner |
| Store | Directory <store>.cbs with deduplicated backups |
| VSS | Volume Shadow Copy Service, snapshot mechanism of Windows |
| WORM | Write Once, Read Many: data is locked against changing and deleting until a point in time |
Manual · Appendix D