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So if you create a backup, you better store it off-site, because if your server goes down,

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your backup will be lost and you can't restore it anymore.

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Now to store files off-system, Linux has a couple of utilities available.

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First, there is SFTP, which uses an SSH process that is running on a remote system to upload

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files using traditional FTP commands.

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I can see one use case only, and that is if you have used traditional FTP very often.

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But nowadays, that's not very common anymore.

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You might like SCP, which is also part of the SSH packets, and it can be used to copy

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individual files over.

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Very convenient on a file-by-file basis.

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But if you really want it to be powerful, you better use rsync.

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rsync is used to synchronize files over to and from remote servers, and it does an excellent

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job making delta-syncs, meaning that it will synchronize differences only.

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Use something like rsync-avz home-student to student-add-192.168.29.139://home-student,

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and your directory will be synchronized with the remote directory.

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Two options that I should talk about in the context of rsync are minus-n.

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Minus-n is doing a dry-run.

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It will show you what it will do without doing it.

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The second option is minus-delete, and that will make sure that if a file in the source

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doesn't exist, but does exist in the target, it will be deleted.

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In my opinion, that's a pretty dangerous option, so better don't use it.

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Let me show you.

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So I'm going to start using scp-student-add-192.168.29.139://etc/.

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Then let me use ls-l hosts, and there we have the host file from the remote machine.

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Now the other example is rsync.

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So how are you going to use rsync to synchronize?

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Well, let me use rsync-avz.

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Hang on.

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Before I'm doing that, let me use touch-home-student-hello-file, uppercase, so that it's easy to see.

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And then rsync-a for archive mode, v for verbose, z because it's cool to apply compression,

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but that's not really needed if you don't synchronize very much.

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Slash home slash student with a slash behind it to slash student-add-192.168.29.139

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colon slash home slash student slash.

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Please do not forget the slashes.

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And then it is prompting for the user student password, and it will synchronize files.

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So if I would use ssh student-add-192.168.29.139 ls-l slash home slash student, then we should

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see the result.

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There we go.

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The result is there.

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So that is how rsync is working.