Synology NAS Package Center Doesn't Connect - Davis Tech Media
Disk vibration was propagating in the furniture which acted as a soundboard. The solution was to put the NAS on a soft mouse pad (here, SteelSeries), and all my trouble was gone. :
Reset Synology NAS – NAS Compares
Amazon.com: Synology 5bay Expansion Unit DX517 (Diskless) : Electronics
Synology gets even better w/ version 5.0: Why every Mac & iOS user should have a DiskStation - 9to5Mac
Synology gets even better w/ version 5.0: Why every Mac & iOS user should have a DiskStation - 9to5Mac