I think it is more some strange quantum entanglement thing :D

some stretch of the slapd code must create the entanglement because it is only the slapd files that get effected.

Since the NAS is n a closet in an old Desktop metal case (read heavy) with the drives (built with their own fairly solid metal cases), and no bananas or radium dial clocks around (I miss radium dials https://en.wikipedia.org/wiki/Radium_dials for those too young to remember them) So unless it is some fantastically specific gamma particle source I'm sticking with quantum entanglement..

(of course it could always be a bug in the software.. but wheres the fun in that :D )

Note: If anyone has wikipedia editing privs. the english description on ( https://en.wikipedia.org/wiki/File:Radium_Dial.jpg ) need to be corrected.. Radium dials never needed to be exposed to UV-a that's part of what made then so cool.. they just kept on glowing all on their own.