Overview
This lecture covers the installation, usage, and advanced features of rsync for file transfer, backup, and system migration, focusing on practical command options and important caveats.
Installation & Front-ends
- Install rsync using your package manager on both source and destination machines.
- GUI front-ends include Grsync (GTK), luckyBackup (Qt), and nbRsync (JavaFX).
- Other tools using rsync: rdiff-backup, osync, yarsync.
Basic Usage & Options
- Use
rsync -P source destination for copying files, showing progress and resuming partial transfers.
- Use
-r/--recursive for directories.
- Remote copying uses the SSH protocol by default (host:destination syntax).
rsync creates a file list and only transfers changed file blocks using checksums.- Useful aliases:
cpr() for copying, mvr() for moving, both using sensible default options.
Trailing Slash Caveat
- Adding a slash to the source directory changes destination structure:
rsync -r source/ dest copies contents directly; rsync -r source dest creates a subdirectory.
- Use scripts or care to avoid accidental overwrites due to trailing slashes.
Backup Utility
- Simple scheduled backup:
rsync -a --delete --quiet /src /dest.
- Use
-e ssh for remote backups: rsync -a --delete --quiet -e ssh /src user@host:/dest.
- For automated backups, scripts can be triggered by cron, NetworkManager, or systemd/inotify.
- Differential backups: use
--inplace --backup --backup-dir=/incr/$DAY for daily differential copies.
- Snapshot backups: use
--link-dest for hardlinked, space-saving snapshots.
Full System Backup & Restore
- Full backup:
rsync -aAXHv --exclude=... / /backup preserves links, ACLs, xattrs, and skips specified dirs.
- Exclude system, cache, bind mounts, swap files, and GVFS errors.
- Restore by reversing source and destination; remove
--exclude options for full restore.
Advanced Filtering & Files-from
- Use a filter file with
--filter="merge backup.filter" for complex include/exclude patterns.
- Use
--files-from=file.txt with a list of paths for custom file selection (add -r for recursion).
File System Cloning
- For full filesystem cloning:
rsync -qaHAXS SRC/ DEST/ preserves hard links, ACLs, xattrs, and sparse files.
- Use trailing slash to avoid directory nesting issues.
Running as a Daemon
- Start
rsyncd.service for network file serving on port 873.
- Configure
/etc/rsyncd.conf with shares and include/exclude lists.
- Data is not encrypted; consider client authentication and firewall settings.
Key Terms & Definitions
- rsync — Utility for fast incremental file transfers.
- Archive mode (-a) — Preserves permissions, links, timestamps, owner, and group.
- Checksum — Integrity check used to transfer only changed file blocks.
- Snapshot backup — Incremental backup using hardlinks to save space.
- Daemon mode — Running rsync as a background network server.
Action Items / Next Steps
- Install rsync and any desired front-ends.
- Try basic rsync commands for local and remote copying.
- Set up and test a backup script suitable for your use-case.
- Review the trailing slash caveat before copying directories.
- Explore advanced filtering or daemon mode as needed.