First, two precautions:
- Be sure to keep a backup of your database file.
- In Options | Preferences | Thumbnails, turn 'auto remove orphans' off (if it isn't already) to prevent that any thumbnails would be deleted if TP doesn't find the corresponding files where it expects them.
- In the same dialog window, turn 'Make thumbnails automatically' off. This helps avoid confusion on fast systems, where you might think that you are looking at your trusty old thumbnails when in fact TP has just produced them on the fly.
can I simply re "build" that mapped drive, or will it lose all my meta data and libraries?
Well, it depends. If ThumbsPlus shows you the old thumbnails (with their metadata etc) AND you can successfully open the files shown in ThumbsPlus, then they're in good shape and TP should not overwrite them when you use the Scan Drive, Scan Tree or Scan Folder commands to create thumbnails for new folders and files.
It's good that you see green and blue folders, but I'm puzzled that you do not see the new folders. I can think of only two explanations for that:
- It's not the new NAS drive after all (but that seems to be contradicted by the green color of the folders within). or:
- The 'Only show folders with thumbnails' option is on in Options | Preferences | Disks & Folders.
When you right-click on that drive in the tree panel, there's an option 'Volume Properties' that shows how that drive has been recorded in the database, and how it currently appears physically. Maybe that will tell you more about which drive (the new one, the old one or both) it represents.
I think the ideal solution, if you have a database backup from when you still used the old drive, would be this:
- Exit TP and restore that copy of the database file. Don't run TP yet.
- Be sure to give the new NAS exactly the same server name, volume label and folder structure as the old one (the server name is tied to the device, so if you only replaced the harddisk within, you won't have to fiddle with the server name).
- When you launch TP now, I would expect it to recognize the new NAS drive as the old NAS drive, and it should show both the old existing thumbnails and the new folders.