Corrupted db when data files are copied in

Hey guys! I’m sure there is a straightforward solution, I’m running a Mongodn service thusly:

I’m having docker map the host’s /data/oqm/db/mongo/ directory, and looks like this works fine; looking from the host I see the directory populated when run. This setup seems to work fine between restarts and persists fine.

However, when I try backing up and restoring the data by copying the data in this directory out then back in (while the mongo service isn’t running), when trying to bring the service back up, Mongo barfs, claiming the data is corrupted. Any ideas?

I am trying this method as described: