Not sure if this use case is supported, but I have the following setup - I use git-annex to store my Lightroom catalog and photos. My local machine does not contain all files, `.mov` files for example are excluded via the preferred content mechanism. The full backup is on a remote server using ssh.

Now I want to create another copy of the data (encrypted) from my local machine to a USB stick or similar. I found that the locally excluded files are not synced. In order to copy all the data I first need to change the preferred content config, execute `git-annex get` to fetch the data, then copy via `git-annex sync myusbremote --content`, then change the local preferred content pattern, then run `git annex drop --auto` to delete the local unwanted content again.

I was wondering if there's a way to sync from one remote to another, without storing any data locallly ? Something like `git-annex sync --from ... --to ...`.
