As a system administrator or just a backup-conscious home user, sooner or later (usually sooner) you will have to deal with backups. Disasters do happen, ranging from electrical storms to drive failures, and one needs to be prepared. We cannot stress enough the importance of having copies of important data. While the whole concept of backup is too long for this article, we will focus on rsync for what’s called incremental backups.
Incremental backups are based on the idea that, once you have a copy of the data you need to backup, consequent backups of the same data should be incremental, meaning that you only update the backup copy with the differences since the last operation occurred, not create another full copy. We will detail here a setup we have at home for backing up important data, but the examples here can be used at larger facilities. Once you get started, you will know what, where and when you need.
If you have a backup server that’s up 24/7, you can create a cronjob to backup your data periodically. Since our example is home-based, we have a backup server, but since it’s not up all the time, we will show you how to do it manually. rsync needs to be installed on both systems, and that’s about it, no other setup chores must be performed, at least in simple cases. Please remember that you are not by all means tied to Linux or other Unix platform : rsync is available also for Windows. If you are worried about security, rsync is working over SSH and can be regarded as a secure replacement for
rcp (remote copy) command, so it’s all good.