Move original files and make symbolic links?

Hi and thanks in advance!

Following situation here:

Source Data

  • 1000 GB Photos on ex. D:/Photos
  • one folder with the most recent photos in there with 600GB ex. D:/Photos/Recent

Backup Data

  • Synology NAS about 100km away from me. Backup via Internet (WebDAV).

everything works fine.

Now I want to move the “Recent” Folder on a new SSD to improve loading times.
That’s where I believe I could get some trouble with my Duplicati backup.
I really don’t want to make an initial backup all over again.
So I had the idea to use a symbolic link from the SSD back to the original location of the folder:

SSD:/Photos/Recent —> SymLink --> D:/Photos/Recent

The question now is, if this will work with my current backup settings in Duplicati?
Can I “trick” Duplicati this way so that it thinks that the “Recent” folder is still in place?


No matter where you place the files, if they’re included in the Duplicati Source folder and they haven’t had their contents changed, it will see their CONTENTS as having already been backed up so won’t transfer the file guts again.

However, it will see the new file paths as new files so will start a new history for them (in other words, if you want to view the history of the files from BEFORE the move, you’ll have to use the old paths).

As for how the symbolic link would be treated, I’m not sure. My GUESS is Duplicati would still see them in the new path.

There is some good documentation on the symlink policy options here:

It might be what is desired but personally I’d be cautious about creating unnecessarily complicated systems to rely on.

Thanks for the link.
I think I don’t get it completely…

--symlink-policy = Store
Use this option to handle symlinks differently. The store option will simply record a symlink with its name and destination, and a restore will recreate the symlink as a link. Use the option ignore to ignore all symlinks and not store any information about them. Previous versions of Duplicati used the setting follow , which will cause symlinked files to be included and restore as normal files.

Especially the last part seems to be the most interesting one for me:

… Previous versions of Duplicati used the setting follow , which will cause symlinked files to be included and restore as normal files. …

So what previous versions of Duplicati did with the setting “follow” would be exactly what I want to achieve in my case - right?
And how do I get the “follow” settings on newer versions?

And yes, I know symlinks aren’t quite the easiest and reliable way to choose in things of file structure :slight_smile: Maybe there is some other way around.
Speaking of which… Question two:
Is it possible to move a folder in the source and in the backup at the same time? So that the connection between them doesn’t get lost?

I think that’s pretty close to what you want. Just be aware that the files will overwrite the symlinks on a restore unless you choose to restore them elsewhere.

When you edit your backup, on the last page, under advanced options you can find the symlink policy option and set it.

The “connection” is really just the full path. Any filename change or moving to a new directory will make Duplicati consider it a “new” file. But it doesn’t really matter since it won’t reupload blocks that are already backed up.

Unless you care about keeping a contiguous history of file changes since any change in a file’s full path (so folder or name) will start a fresh history at the new ‘location’ - but as stated it will NOT re-upload unchanged parts of the file even if the name/path does change.

I guess, but we don’t have a UI for displaying this history so it’s kind of an imaginary concept that we as users force on top of the data structure.

It would be cool if we could make a consistent history across time for each file but it’s very restricted since we work with snapshots rather than real time backup.

Good point, I need to stay focused on what is rather than what could be. :slight_smile:

The file history is not important for me.
Do I understand it right that Duplicati “knows” my files by the filename even if the path changes?
So if I move one folder ex. “Recent” from one disk to another, then add the new path to my duplicati backup, the folder and its contents would not be re-uploaded?

Well, it doesn’t know the file by name, but it knows it’s contents.

As soon as you try to back it up it skips it unless it has changes. If it has changes it backs up the changes.

Ok perfekt! Thanks to all of you very much!
I’ll give it a try when my new SSD arrives!