This is the backup script designed to run every 6 hours on tachyon.

6h-backup

#!/bin/sh
if [ $EUID != 0 ]; then
    echo -e '\e[31mError: this script needs to be run as root'
    exit 1
else 
    rsync -aHAX --delete-during --exclude={/lost+found,/var/lib/docker} /mnt/root/ /mnt/arch-backup
    if mount | grep -q /mnt/data0-backup; then
        if [ -d /mnt/data0-backup/ToMove ]; then
            echo -e '\e[31mWarning: there are files to move from data0-backup/ToMove. This directory will be copied to data0.'
            cp -rp /mnt/data0-backup/ToMove /mnt/data0/ToMove
        fi
        rsync -a --delete-during /mnt/data0/ /mnt/data0-backup 
    fi
fi