bi-directional webdav sync

[sappel]

Hello everyone,

I'm currently trying to sync my QNAP (TS-212) to a webdav server.

Right now I'm trying to mount the webdav to qnap, but since already this step fails, it's hard to look into bi-directional syncing options.

My QNAP is the main file storage. Due to speed issues, I already uploaded all the files of one share to one of my webservers (~170GB). Some friends need access to my files from time to time, and since my connection is pretty slow, I want to sync my QNAP to my webdav server. In 90% of the situations, a pure backup would be enough, but sometimes they put files on the webdav server, which need to be synced to my QNAP again - so a two-way-sync or bi-directional sync is what I'm looking for.

Anyone has a good hint how to accomplish that?