In earlier versions of MongoDB, you could use the copyDB command or its helper method, db.copyDatabase() to copy a database.

MongoDB has since deprecated these. Also, starting in version 4.2, MongoDB has removed the copydb command, and therefore also the db.copyDatabase() method, which means that you can’t use them even if you wanted to if you’re using MongoDB 4.2 or later.

Fortunately, there’s another way to copy a MongoDB database.

Check for MongoDB Database Tools

In MongoDB, you can clone a database using the MongoDB Database Tools. Specifically, you can use mongodump and mongorestore.

The MongoDB Database Tools are a suite of command-line utilities for working with MongoDB.

If you’re not sure whether you have the MongoDB Database Tools installed, try running the following commands in your Terminal or Command Prompt to check:

mongodump --version
mongorestore --version

That specifically checks for the mongodump and mongorestore versions.

If you don’t have them, you can use the installation instructions over at the MongoDB website to install MongoDB Database Tools on to your system.

Example of Cloning a Database

You need to run mongodump and mongorestore from your system’s command line (e.g. a new Terminal or Command Prompt window). Don’t run it from the mongo shell.

Here’s an example of code that clones a database:

mongodump --archive --db=PetHotel | mongorestore --archive  --nsFrom='PetHotel.*' --nsTo='PetHouse.*'

In this case, we backup the PetHotel database, then restore all of its collections to a database called PetHouse. In other words, we cloned the PetHotel database as PetHouse.

This uses mongodump to create a backup file of the database, then mongorestore to restore that database under a different name. We did this by dumping the database to the standard output stream and piping into mongorestore.

Here’s what each parameter does:

Parameter	Description
--archive	Writes the output to a specified archive file or, if the archive file is unspecified, writes to the standard output (stdout). In our case, the archive file is unspecified, so it wrote to the standard output.
--db	Specifies a database to backup. In this case, we backup the PetHotel database.
--nsFrom	Specifies the collection in the dump file. The asterisk wildcard (*) specifies all collections.
--nsTo	Specifies the collection name that should be used in the restored database.

You can also use mongodump to dump all databases. To do that just run mongodump without any arguments. However, when you do that, it doesn’t include the local and config databases in its dump.