alt Hacker NewsThe "easiest" way is to use bind mounts to a local directory (or multiple directories) instead of volumes. Then you can just use normal backup tooling.
Docker volumes (and bind mounts) however have the minor problem of being hard to get a consistent copy to without stopping the service. You can work around this by, e. G., having ZFS or btrfs as the underlying FS and making a snapshot there. Otherwise, your software (like PostgreSQL) might also have other online backup tooling.
AFAIK volumes are nothing more than a bind mount on a private docker folder, e.g. the files for volume my-volume are stored in /var/lib/docker/volumes/my-volume/_data, so backup strategies (an problems) for bind mounts apply also to volumes