"synotify_add_watch" with a path sounds suspiciously like the "inotify_add_watch" function ( Reference ) in Linux. It's possible that Synology has extended this function to support their special disk configurations (SHR?), and this support is not available (or not present) in the PVSCSI drivers being used for VMWare/ESXi. In which case, it will take some reverse engineering to resolve.
Alternatively, there could be an error in the DSM Shared Folder Sync functionality. The first thing that comes to mind is the [space] in the directory name. It's possible that there is an error in the code, which has been corrected/updated in the newer DSM version. For reference, check out my post above:
Synology DiskStation DS3612xs Release Notes
Version: DSM 4.2-3211
(2013/04/18) - What's New
Improved stability when syncing files between two DiskStations with Shared Folder Sync.
My first attempt at a fix, would be to remove the [space] in the directory name and try the Shared Folder Sync configuration/setup again. Gut feel says that this has a high chance of working.
Thanks mate for your reply!
I'll give it a try. Although the folder I'm trying to sync is not with spaces. The name of the Sync Set is called Foto Sync (with a space).
But never the less I'm going to give it a try and report back here.
cheers