The server disaster recovery feature for web/db/email servers planned for May, may run into early June will rely on the Enhance backup system. The functionality will allow you to mark a server as "dead" and restore its sites to another server within your cluster from the last available backup, with all DNS (and CloudFlare if enabled) being updated automatically. This will also work with the upcoming S3 backup target.
We can potentially add a 3rd option in the future for customers who are not using Enhance's backup system. This would recreate the sites but without any of the website data, allowing you to restore it from your external backup system instead.
The probability of a complete server failure is very low and therefore I think a block level backup in addition to Enhance's website/email data backups is sufficient for most usage cases.
If you want to back up individual files, the strategy might look something like:
- /var/local/enhance but excluding /var/local/enhance/containers
Back up docker containers with "docker commit" and "docker save"
Back up docker volumes - you can probably directly back up /var/lib/docker/volumes
However restoring from these files into a consistent state is going to be difficult and is not recommended. Restoring a block level backup is likely to be faster.