Update: Never mind, i figured it out. I just deleted the folder i was trying to select as the target and re-created it from the PI and it worked fine. Must have been some weird permissions thing with mapping an NFS share from a windows server to a Linux client or something sync didn't like about it OK, so I'm having issues getting sync to write into a mounted NFS share on Linux. first some background: there are 3 machines involved. 2 windows servers (one is 2016, the other 2008) 1 Raspberry PI The Server 2016 server is a host on my network and is my main file server and database server The Raspberry PI is a host on my network in the DMZ and is the one running sync The Server 2008 server is a VPS that has files i want to back up from semi-regularly and is also running sync my issue is that if i expose an NFS share on the Server 2016 box, then mount it on the Pi, i can write to said share with any user (even running sudo -u nobody touch /mnt/VPS-backup/test.text works absolutly fine), however sync reports that i don't have permissions to write to said folder when i try to add a manual connection. So I'm wondering, is this kind of thing not possible with sync (ignoring the obvious issue that if sync starts and the NFS share isn't mounted, it may just assume the folder is empty and sync the VPS server accordingly, which is fine because a script copy's the files to be backed up into a temporary folder which is synced) or am i missing something?