rsync: A Backup Strategy for Modern Times - Page 3
Dry-Run
$ rsync -avn -e ssh sourcedir username@remotemachine.com:/destinationdir/
The -n switch, or --dry-run, shows what will happen when rsyn is run but without actually copying or changing anything. Use with -v, verbose, to see the messages. Verbose has three levels: -v, -vv, and -vvv for maximum verbosity. Always perform dry runs until you're satisfied rsync will work as desired.
Some other useful command options to be aware of include:
- --delete = Use with caution! Always do a dry-run first when using --delete. Don't say I didn't warn you! --delete removes all files at the destination that do not exist on the source.
- --delete-excluded = Delete any files that are named by --exclude. As you can see, this is powerful stuff to keep archives tidy and uncluttered. Use it wisely.
- -z (or --compress) = Use rsync's compression.
- -S (or --sparse) = Handle sparse files efficiently.
- -H (or --hard-links) = Preserve hard links. -a does not preserve hard links.
- -b (or --backup) = Appends a ~ to existing destination files. You're not stuck with "~", as the --suffix command lets you specify anything you like
- --backup-dir=DIR = Combine with --backup to tell rsync where to store backups.
Excluding Files
rsync can be exclusive as well as inclusive:
--exclude pattern = Exclude files matching pattern.
--exclude-from file = Exclude patterns listed in file.
For example, --exclude *.tmp will exclude all .tmp files. --exclude *.bak excludes .bak files. Name individual files and directories. Each --exclude can take only one argument. For multiple excludes, either string them together on the command line:
--exclude *.bak --exclude *.tmp
Or better, put them in a file:
--exclude-from exclude.file
rsync now supports regular expressions, as all good Linux programs should, for fine-grained file selection. It requires applying a patch; follow this link for details.
Page 4: Running an rsync Server