Mongorestore don't know what to do with file "db/collection.bson", skipping

Question

I want to migrate my mongodb from 2.0 to 3.0. So I followed the official doc to use mongodump to backup my dbs and use mongorestore to restore the dbs to mongodb 3.0.

But when I use mongorestore, it tells me "don't know what to do with file "db/collection.bson", skipping...".

Nothing to do. How could I migrate my dbs?

Thanks.

EDIT: Here is my steps.

Use mongodump in mongodb 2.0

mongodump tree dump     db     ├── collection-1.bson     ├── collection-2.bson     ├── collection-3.bson     ├── ... 

Copy db directory to mongodb 3.0 server.

On the mongodb 3.0 server calls mongorestore db

But I get this error:

mongorestore db 2015-03-10T09:36:26.237+0800    building a list of dbs and collections   to restore from db dir 2015-03-10T09:36:26.237+0800    don't know what to do with file "db/collection-1.bson", skipping... 2015-03-10T09:36:26.237+0800    don't know what to do with file "db/collection-2.bson", skipping... 2015-03-10T09:36:26.237+0800    don't know what to do with file "db/collection-3.bson", skipping... ... 2015-03-10T09:36:26.237+0800    done 

Answer 1

It seems one must also specify -d in 3.0 like this:

mongorestore -d db db 

Answer 2

This answer isn't directly related to your issue case, but the same error output you will receive trying to restore mongo data, dumped with --archive option, available since MongoDB 3.2 version. To resolve this you need to specify --gzip parameter in your mongorestore command. Example:

mongorestore -d destination_db --gzip /path/to/source/db