Installation

On your client

Make the hostname for your raspberry pi available on your client, e.g. by editing /etc/hosts:
```
<ip-address>        raspberrypi
```

Enable the rsyncd service and run it on a nice level of 10 or something. On my machine it worked by installing a systemd service by creating /lib/systemd/system/rsync.service:

[Unit]
Description=fast remote file copy program daemon
ConditionPathExists=/etc/rsyncd.conf

[Service]
ExecStart=/usr/bin/nice /usr/bin/rsync --daemon --no-detach

[Install]
WantedBy=multi-user.target

Enabling and starting it via

sudo systemctl daemon-reload
sudo systemctl enable rsync
sudo service rsync start

Export the folder you want to backup as backupsrc via rsyncby adding the following to your /etc/rsyncd.conf

#global (globale einstellung)
log file = /var/log/rsync.log
timeout = 300

[backupsrc]
path = <backup-path>
comment = <some comment>
max connections = 1
hosts allow = raspberrypi
hosts deny = *
use chroot = yes # Don't know what this does
list = true # Maybe no?
uid = root # No clue
gid = root # No clue
read only = true # Sound's good

Maybe you need to restart the rsync daemon afterwards.

On the raspberry

To install the scripts, clone the repository onto the raspberry and make it accessible to root (i.e. clone it into /root).
Add an entry to your /etc/fstab to mount the backup destination to /root/snapshots:
```
UUID=<uuid-of-your-backup-drive>  /root/snapshots  ext4  ro,suid,dev,noexec,nouser,async,noauto  0  0
```
You can determine the UUID using sudo lsblk -o +uuid.
Make the hostname for the machine you want to backup available on your raspberry pi, e.g. by editing your /etc/hosts:
```
<ip-address>        backup-client
```

Create cronjobs which do the backups using crontab -e as root:

# m h  dom mon dow   command
# Run an hourly backup every hour.
0 * * * * /root/backupsrv/take_snapshot.sh --host backup-client --turnus hourly --count 4

# Use the latest hourly snapshot as a daily snapshot every day at 07:45.
45 7 * * * /root/backupsrv/rotate_snapshot.sh --host backup-client --turnus daily --count 7 --turnus-fast hourly --count-fast 4

# Use the latest daily snapshot as weekly snapshot every monday morning at 03:00
0 3 * * 1 /root/backupsrv/rotate_snapshot.sh --host backup-client --turnus weekly --count 4 --turnus-fast daily --count-fast 7

Now your raspberry should be setup make rotating backups if your machine is available when the cronjobs execute.

Providing snapshots to client

Export /root/snapshots as read only NFS mount to your backup client and configure your backup client to mount it someplace, e.g. /snapshots.

TODO: Specify

Reference

The scripts are based on the following articles:

stefanbuettner/backupsrv

Installation

On your client

On the raspberry

Providing snapshots to client

Reference