I have a backup of my old db with WiredTiger.
I am using folder per db.

Trouble appears with the way engine work.
Old version have created two folders: collection and index,
New version creates a file collection-...wt and index....wt

I was thinking with just paste the folders I could restore my db but

1. My db folders are not recognized, How can I 're-attach' them??
2. How can I migrate my old folders to the new structure?