The backups in CoreELEC work very well and they have solved me several times, always related to the nightly version test, the system restoration. As a precaution I am using the /storage/.config directory to save my stuff and include them in the backup. The biggest problem is that the backup does not include the /storage/.opt directory where the entware servers are.
I request the inclusion of the /storage/.opt directory in CoreELEC backups.
The solution I am using to solve this problem is to make an automatic weekly backup as follows:
File /storage/.config/autostart.sh
…
crontab /storage/.config/scripts/crontab.conf
…
File /storage/.config/scripts/crontab.conf
0 7 * * Mon /storage/.config/scripts/backup-and-reboot.sh
0 7 * * Tue systemctl reboot
0 7 * * Wed systemctl reboot
0 7 * * Thu systemctl reboot
0 7 * * Fri systemctl reboot
0 7 * * Sat systemctl reboot
0 7 * * Sun systemctl reboot
File /storage/.config/scripts/backup-and-reboot.sh
#!/bin/sh
# stop main services
systemctl stop kodi
systemctl stop service.softcam.oscam
systemctl stop service.tvheadend42
systemctl stop entware.service
# save logs for entware servers
mv /opt/var/log/messages /opt/var/log/messages.old
mv /opt/var/log/zerotier-one.log /opt/var/log/zerotier-one.log.old
# full backup
mv /media/<external-hd>/backups/full-backup.tar /media/<external-hd>/backups/full-backup.old.tar
tar cvf /media/<external-hd>/backups/full-backup.tar /storage/.kodi /storage/.cache /storage/.config /storage/.opt
systemctl reboot