I don’t go the dd way. My Cloud Servers are doing
restic backup --exclude="/var/cache/*" --exclude="/proc/*" --exclude="/sys/*" --exclude="/tmp/*" --exclude="/var/tmp/*" /
every night and it’s fine for me. If necessary, I stop some daemons (like database servers) before to be sure everything is consistent.
I also tried full restores, which I described here some time ago.