What to run:
rsync -HPva --delete <source>/ <dest>/(tip for remembering: "Arr! Sync! Hey, Pretty view, eh? Do Eet")
why:
-H(--hard-links) sync any hard links as hard links, as distinct from files, at the destination-Pv(--partial --progress --verbose) gives you a nicely verbose output with a reasonable way to estimate remaining time (sometimes)-a(--archive) "equals-rlptgoD", that is "please just work"--deleteremoves files from the destination that are not present on the source (it doesn't delete from the source)
Notes:
- running rsync multiple times will pull file metadata in to VFS cache, making subsequent runs much faster (good for priming before an outage)
- put trailing slashes on
<source>and<dest>ination paths to ensure directories are created the way you expect
Sometimes good option:
-z(--compress)- good if you're transferring over the internet or narrow-band medium
- bad on localhost