After several years of development I am proud to announce the availability of the syncosync backup appliance. It is Free and Open Source Software and could be useful for everybody who wants to combine local and remote backups with low costs and very fast disaster recovery capabilities. We are a small group of developers and are using the prototypes with Déjà Dup since > 4 years.
The name of the project is “syncosync” the starting point to understand more is https://syncosync.org
So the idea is to have a Raspberry Pi4 with a decent big enough HDD at your place and exactly the same thing at a friends place (your backup buddy). The HDDs are (normally) partitioned equally which means, that 50% of the disk space is for you, the other 50% are for your buddy.
You are putting your backups via Déjà Dup on your local syncosync box using encryption and sftp and the rest is done by syncosync: the backups are synced to the buddies syncosync box and so they are always and automatically held also remote. This is also the reason, why you do not need any raid for your local backup. The remote HDD is the mirror of your local HDD.
When the maximum disaster has happened: you lost all your local data, you can visit your backup buddy, grab his syncosync box, buy a new laptop and restore your data with the speed of the local network. Alternatively - if you have the time - you can restore from your buddy via remote restore.
The whole syncosync system is operated via WebUI, there is no need for any commandline setup - which is possible though as there is a separation between core and UI. The backup per system is based on separated backup accounts, so your whole family or small company could use one syncosync system.
Right now the UI is available in English and German, we hope other languages will happen soon, there is a weblate project set up to support that.
Please give syncosync a try, we think it is a perfect alternative to cloud services and also a much better automation of backups than remote manually stored harddisk drives. There is a forum, the source code is on gitlab, the translation is on weblate, manuals are available in English right now - there is also a subsection how to use duplicity with it.
There is a small section how to configure Déjà Dup to use syncosync as a backup destination.