Rsync checks the files and only issues the copy if the file size/modified dates are different by default. Ignore existing will not overwrite a changed file afaik.
If the file is large it only sends the changed blocks (e.g. you have a 100gb database and only a dozen 4mb blocks have been modified it won’t send the full 100gb across the network)
I like to add --ignore-existing to it aswell in case it gets interrupted. Useful when it’s a timed backup or similar
If it doesn’t ignore existing by default, what’s the difference between that and plain old copy?
Rsync checks the files and only issues the copy if the file size/modified dates are different by default. Ignore existing will not overwrite a changed file afaik.
If the file is large it only sends the changed blocks (e.g. you have a 100gb database and only a dozen 4mb blocks have been modified it won’t send the full 100gb across the network)