How do I copy a database from one MongoDB server to another?

I have two mongodbs in different server, both start with --auth. Now I want to copy a db from one server to another.

> mongo
> use admin
> db.copyDatabase("mydb","mydb","another_server")

It shows:

{ "errmsg" : "", "ok" : 0 }

And:

> db.getLastError()
null

Seems no error, but the copy is not successful. What's the correct command to use?

If you are using --auth, you'll need to include your username/password in there...

Also you must be on the "destination" server when you run the command.

db.copyDatabase(<from_db>, <to_db>, <from_hostname>, <username>, <password>);

If all that doesn't work, you might want to try something like creating a slave of the database you want to copy ...

Starting from Mongo version 3.2 you can do it by using mongodump/mongorestore:

mongodump  --host <from_host> --db <from_db> --archive | mongorestore --host <to_host> --archive

Additional info could be found at:

https://docs.mongodb.com/manual/reference/program/mongodump/ https://docs.mongodb.com/manual/reference/program/mongorestore/

To make remote mongo reachable you can create ssh tunnel to it:

creates a tunnel to the remote mongodb server and tunnels it through port 27117 to the local client

ssh -fN -L 27117:localhost:27017 <remote_host> 

In this case the command to run on the local machine you want to restore to could be:

mongodump  --port 27117 --db <from_db> --archive | mongorestore --archive

In addition to the answer of Justin Jenkins keep in mind that you also can use a ssh tunnel if you don't have mongodb exposed to the network (localhost only)

I use screen to switch between "tasks". for my convenience the ssh tunnel and mongo are executed in separate screen tabs.

step 1: create a tunnel

ssh username@yourdomainOrIP -L 27018:localhost:27017
...Enter your password

step 2 :

mongo
use admin
db.copyDatabase(<fromdb>,<todb>,"localhost:27018",<username>,<password)

In addition to the answer of Mike Shauneu, if your database name on the destination server is not the same as on the source server you need to rewrite the namespace. In combination with authentication I got this to work using the --uri option, which requires a recent mongo version (>3.4.6):

mongodump --uri="mongodb://$sourceUser:$sourcePwd@$sourceHost/$sourceDb" --gzip --archive | mongorestore --uri="mongodb://$targetUser:$targetPwd@$targetHost/$targetDb" --nsFrom="$sourceDb.*" --nsTo="$targetDb.*" --gzip --archive

The following worked for me to copy from Ubuntu Server to another Ubuntu Server, both running MongoDB v4+:

1. The following command should be executed from the server, where you want to restore the database:

   ssh -fN -L 27018:127.0.0.1:27017 <remote_host_ip>

2. Now we have mapped our remote server database to our local server port 27018. Next, we can copy from remote server to our destination server using MongoDB's mongodump/mongorestore pipeline:

   mongodump --port 27018 --db <remote_db_name> --username <remote_db_username> --password <remote_db_password> --archive | mongorestore --username <destination_db_username> --password <destination_db_password> --archive

3. [OPTIONAL] You can check your restored database as followings:

   mongo --authenticationDatabase "admin" -u <destination_db_username> -p

   show dbs

Check if your database exists in the list.