I'll describe my setup and you can get whatever you want from it...
I'm stuck in limbo:
- between a Mac, iTunes, iTunes media files on external 6TB drive, and backups to other external drives
- and DS218+, 4TB SHR internal, and eSata 5TB external accessed by AS, VS, and Plex
Since my media files are already on and backed up by the Mac then I don't want to use up the NAS's internal SHR storage with media files. Not 100% true since music and audiobook files are less than 100GB so they are on SHR at /music. But all video is arranged on the Shared Folder linked to the 5TB eSata drive.
To be sure that only non-DRM media is maintained on the NAS I have set up daily CCC v5 tasks that filter out iTunes propriety stuff but filter in new files. Different tasks for movies, TV shows, TV one-off (they are better tagged using MovieDB so a separate NAS folder and VS 'movie' library), and home movies.
In VS (and Plex too) create a library for each CCC task's destination folder and based on the type of media it contains. Also, make sure that DSM indexing service will pick up these folders as video type.
Then let VS go through and tag the media according to what it finds in TVDB and MovieDB. Next you'll have to go through and correct tagging mistakes, and this could take quite sometime.
IMPORTANT BIT ... Once everything is as you want it you should open VS's admin settings and for each library: highlight and click 'Export Video Info'. This will create a vsmeta file for each item and these 'should' be read whenever VS does its re-indexing.
If you boot the NAS without the external drive then VS will reindex and have empty libraries. But my eSata is always powered so it's rare that the NAS reboots without the drive being offline so I can't 100% say what happens. But I do know that having the vsmeta files speeds up and populates correctly the libraries when I force a re-index by opening a library config (in admin settings) and click Save to close it.
Only once do I remember either booting the NAS without the drive online, or was it I accidentally eject the drive, but the rebuild was helped with having the vsmeta files.
It may also be helped by my VS script that edits age classifications and can apply the lock tag to items when writing back. When an item is locked then it won't update from the Internet searches.