This can be used to snapshot an entire server, useful for keeping a copy before migrating a VPS, for example.
rsync -avxHAX --progress server.example.com:/ ./local_backup_dir
The options are:
-a : all files, with permissions, etc..
-v : verbose, mention files
-x : stay on one file system
-H : preserve hard links (not included with -a)
-A : preserve ACLs/permissions (not included with -a)
-X : preserve extended attributes (not included with -a)
-W : this is --whole-file, prevents trying to do delta copies
--numeric-ids : keep the original UID/GID number, don't remap