Rsync Backups and Hardlinking

I've been looking for a good way to back up files on a remote server. Two solutions I've found are as follows:

• Rsync and hardlinks: http://www.mikerubel.org/computers/rsync_snapshots/
• Rsync and SSH: http://troy.jdmz.net/rsync/index.html

The first link describes an approach for creating incremental backups by using hardlinks to files on the same server (hardlinks don't take up any extra space) and then rsyncing the copies to another server. I suppose you could do the same thing by creating a diff of the backed-up directory and storing it on Amazon S3.

The second link describes how to setup a cron job to rsync files securely to a remote server over SSH without using any passwords by setting up an SSH key.

Combining these two approaches should result in a very flexible backup solution.

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