Do you want a good backup of your stuff? Of course you do!
I use this script that utilized rsync to backup my entire data storage (in a raw, file-based format) to a separate disk and server:
#!/bin/sh
rsync -avz -e "ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null" --progress www-data@dantooine:/data/jwinn/files/ /home/jwinn/Backup
…put this in your crontab, and you are all set:
# Backup ALL of data store for Nextcloud....
0 3 * * 7 /home/jwinn/bin/backup-nextcloud.sh >/dev/null 2>&1