Title: Using rsnapshot for easy backups

	Title: Using rsnapshot for easy backups
	Author: Solène
	Date: 10 January 2020
	Tags: openbsd
	Description:

	## 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
	`/etc/rsnapshot.conf` that you can edit for your needs (you can make a
	backup
	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**.
	`/home/solene/` means that into target directory, it will contains the
	content
	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
	`retain` line will be deleted.


	## New to crontab?

	If you never used crontab, I will share two important things to know
	about it.

	Use MAILTO="" if you don't want to receive every output generated from
	scripts
	started by cron.

	Use a PATH containing /usr/local/bin/ in it because in the default cron
	PATH it
	is not present. Instead of setting PATH you can also using full binary
	paths
	into the crontab, like /usr/local/bin/rsnapshot daily

	You can edit the current user crontab with the command `crontab -e`.

	Your crontab may then look like:


	PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/X11R6/bin:/usr/local/bin:/usr/l
	ocal/sbin
	MAILTO=""
	# comments are allowed in crontab
	# run rsnapshot every hour at 0 minutes
	0 * * * * rsnapshot hourly
	# run rsnapshot every day at 4 hours 0 minutes
	0 4 * * * rsnapshot daily