some assets have volumeId set to NULL in database I noticed that some of my assets have volemeId column set to NULL in the database table assets.

Is it normal? Should I attach them manually to some volume?
Is it normal?


Yes. It's a nullable column in the database.


  Should I attach them manually to some volume?


Nope. There are many scenarios where Craft creates temporary volumes and temporary assets where they won't belong to an "official" volume.