• can be used over own proto without encryption (ssh) overhead
• no build-in incremental snapshots support
• incremental backups of modified files possible (using –backup and –backup-dir params)

• like rsync
• incremental snapshots support. Each snapshoot looks like full source tree. Space is not wasted because hardlinks are used.

• Mirrored structure is available at destination (like rsync). Easy to browse.
• ACL and extended attributes support
• Update is slow
• special directory rdiff-backup-data are also created at dest where old versions are kept
• http://www.nongnu.org/rdiff-backup/

• No direct access to backups. Backups are stored in PGP encrypted/compressed tar volumes.
• Restarting of broken backup needs only to re-download first volume from destination

• front end to duplicity

Backups to NSA310 over fast ethernet. Hard disc encrypted with software ARM-optimized AES. Average network copy performance 6-8MB/s. About 22GB of small files.