Using rsnapshot for easy backups

• Author: Solène
• Date: 10 January 2020
• Tags: openbsd

NIL## Introduction

rsnapshot is a handy tool to manage backups using rsync and hard links on the

filesystem. rsnapshot will copy folders and files but it will skip duplication

over backups using hard links for files which has not changed.

This kinda create snapshots of your folders you want to backup, only using

rsync, it's very efficient and easy to use, and getting files from backups is

really easy as they are stored as files under the rsnapshot backup.

Installation

Installing rsnapshot is very easy, on most systems it will be in your official

repository packages.

To install it on OpenBSD: pkg_add rsnapshot (as root)

Configuration

Now you may want to configure it, in OpenBSD you will find a template in

of it first if you want to start over). As it's stated in big (as big as it can
be displayed in a terminal) letters at the top of the configuration sample
file, you will see that things must be separated by TABS and not spaces. I've
made the mistakes more than once, don't forget using tabs.

I won't explain all options, but only the most importants.

The variable `snapshot_root` is where you want to store the backups. Don't put
that directory in a directory you will backup (that will end into an infinite
loop)

The variable `backup` is for telling rsnapshot what you want to backup from
your system to which directory inside snapshot_root

Here are a few examples:

    backup	/home/solene/	myfiles/
    backup	/home/shera/Documents	shera_files/
    backup	/home/shera/Music	shera_files/
    backup	/etc/	etc/
    backup	/var/	var/	exclude=logs/*

**Be careful when using ending slashes to paths, it works the same as with rsync**.

of /home/solene/ while /home/solene will copy the folder solene within the

target directory, so you end up with target_directory/solene/the_files_here.

The variables retain are very important, this will define how rsnapshot keep

your data. In the example you will see alpha, beta, gamma but it could be hour,

day, week or foo and bar. It's only a name that will be used by rsnapshot to

name your backups and also that you will use to tell rsnapshot which kind of

backup to do. Now, I must explain how rsnapshot actually work.

How it work

Let's go for a straighforward configuration. We want a backup every hour on the

last 24h, a backup every day for the past 7 days and 3 manuals backup that we

start manually.

We will have this in our rsnapshot configuration

retain	hourly	24

retain	daily	7

retain	manual	3

but how does rsnapshot know how to do what? The answer is that it doesn't.

In root user crontab, you will have to add something like this:

# run rsnapshot every hour at 0 minutes

0 * * * * rsnapshot hourly

# run rsnapshot every day at 4 hours 0 minutes

0 4 * * * rsnapshot daily

and then, when you want to do a manual backup, just start rsnapshot manual

Every time you run rsnapshot for a "kind" of backup, the last version will be

named in the rsnapshoot root directory like hourly.0 and every backups will be

shifted by one. The directory getting a number higher than the number in the