Backup Destination

I have installed Duplicati in a container on my NAS. What “Backup Destination” should I select to be able to access the host directories? Of course local does not work because it is in a container.

Welcome to the forum!

Normally people use a remote destination, often cloud storage. The source folders would be local NAS folders that you want to back up. If you are using a docker container then by default you can’t see anything on the host machine (NAS). You will need to use bind mounts to gain access to the host filesystem.

If you are new to docker, make sure you are also using a bind mount or volume mapping for your the container’s /data folder (assuming you are using the official docker Duplicati image). Otherwise important Duplicati data (its configuration database and backup databases) will not be retained when your container is redeployed (like when a new version is released). Docker containers are meant to be easily deletable and redeployable - data inside the container is not retained. Read more here and other sections of that documentation site.

If your goal is to back up OTHER machines TO the NAS, then you would want to install Duplicati on those machines and select your NAS as the backup destination.

Thank you for the detailed explanation!
I’m actually looking for an agentless Backup solution. On the NAS the “Backup Server” and on the client (desktop or laptop) an OS running which provides access for the NAS e.g. via SMB to volumes which are not in use. I don’t like to install a backup software on exactly the OS I want to save.
To save partition images I have a solution with DFSEE an some REXX scripts. I also would like saves from where I can restore a single file.

Duplicati is not a client/server type of solution. It is a standalone backup program that really works best being installed on each device that has data you wish to protect.

That being said, you may be able to get it to work by installing on your NAS and having your NAS reach out to client machines. On Windows (which I’m pretty sure your NAS is not) you can manually enter UNC paths for the source data. This works as long as the user credentials that Duplicati is running as are valid on the remote machines. This is because Duplicati provides no authentication mechanism when specifying source folders.

If your NAS is Linux-based, you cannot use UNC paths. Instead the only method I’m aware of accomplishing this is to mount the remote shares/volumes on the NAS. Then they appear as “local” folders and you’d be able to select them for backup in Duplicati.

Both solutions are messy in my opinion. I’d recommend you instead use Duplicati as designed and install on each device that has data to protect. Maybe one thing you are trying to avoid is difficulty of monitoring several independent installations. There are some solutions for that, both built-in to Duplicati (email alerts) and 3rd party solutions (https://www.duplicati-monitoring.com).

Now I have a much better picture of Duplicati. What you say makes sense about using it as designed. Therefore I will look for a product I can install on my NAS and which is able to access all my devices in my home net.
Thanks for your effort!

Happy to help… Good luck on your search!

Have a look at UrBackup. Supports backup of data and complete filesystems as images.