> I run the SRFI domain and others on Linode, which takes snapshots
> several times a day.  If you have something like that available, that
> would be great, but tar would work, too.

AFAIK all of the big VPS providers have snapshots.

I'm not sure whether it plays well with SQL databases. Gitea's
documentation advises to stop the Docker container, then use
PostgreSQL's dump feature, then restart the container. They say this is
the only sure way to avoid database consistency issues.

The dump feature produces a big text file containing SQL code to
recreate the database. AFAIK this is the de facto standard way to back
up databases. This dump can be combined with non-SQL assets like git
repos, then tarred up and timestamped.