I installed BitTorrent Sync on the MBL 3TB and it is running perfectly. The downside is that the device is not going to sleep anymore.
I stopped btysync and could confirm that this is actually the problem. In the btsync config I set the rescan interval to 12h but with no help.
The issue was posted @ the BitTorrent forums already and the reply was that the newes version of btsync should fix this. I am running an even newer version and still have the problem.
Is anybody here using btsync and has some tipps or workarounds?
here is the link to the btsync thread: forum.bittorrent com/topic/20524-btsync-prevents-nas-to-enter-sleep-mode/