3 ms·

Rsync always sends a list of files (and their attributes). But typically most files haven't changed. They could just send the files that have changed since t

• ars 13y ago
  It doesn't know which files exist on the server. And the file can change on the server just as easily as the client. So how can it tell this without sending the complete list?
  • ape4 13y ago
    Yes in the general case. But in the case of a backup that's done daily the sender can say... there are all the files that changed since we last did this.
    • ars 13y ago
      Rsync is designed for the general case. It's useful for backups, but not designed for them.
    • tnhh 13y ago
      In this case, I think you want to be using unison rather than rsync.
• general_failure 13y ago
  Yes, but rsync doesn't store any state for each xfer.
• beagle3 13y ago
  rsync already supports that. It has an "offline"/"batch" mode - you can generate a diff, only send that, and apply it at the other end. However, you are unlikely to save any traffic that way. rsync is super efficient and does not necessarily send complete directory listings.