I want to use it to do a nightly "backup" of files from a computer where the files will change several times a day but only want to backup once a night. Is this possible?
I prefer to use rsync, and to schedule it as a cron job. This command will get it done for you:
I like rsync because it's sole purpose is to intelligently synchronize directories and their contents. Rsync maintains all file attributes, and also copies hidden files. It does not recopy files that have not changed since the last backup. I prefer this because it provides direct and quick access to the copies without any special programs. They are simply copies of my files, in the exact layout as the original. This method will not store previous backups however, so that is something to consider if you care about previous backups. I personally don't want to use the disk space on backup history.
To schedule it on a cron job, open up the crontab like so:
Then add this line:
This will run the job every night/morning at 2:01 AM. Full instructions here.
Use "Deja Dup" (also known as "Backup"). Set the "How often to backup" in "Schedule" tab to "Daily"
You can use Unison, which is available from the Ubuntu repos. You can install it via software center.
It builds over the rsync, and syncs edits and deletes from multiple places. So if you have data files which are present on multiple machines, then editing files on one machine would give you tough time while syncing in other machine. Multiple edits (to different files) across such server copies are also tough to sync with rsync.
Unison handles all this, and gives you a clean CLI or GUI to work with. Version 2.40.65 recommended.
You must install the same version of unison at both primary(ies) and backup server(s).