copydb

The copydb command copies a database from a remote host to the current host. The command has the following syntax:

{ copydb: 1:
  fromhost: <hostname>,
  fromdb: <db>,
  todb: <db>,
  slaveOk: <bool>,
  username: <username>,
  password: <password>,
  nonce: <nonce>,
  key: <key> }

All of the following arguments are optional:

• slaveOk
• username
• password
• nonce
• key

You can omit the fromhost argument, to copy one database to another database within a single MongoDB instance.

You must run this command on the destination, or the todb server.

Be aware of the following behaviors:

• copydb can run against a slave or a non-primary member of a replica set. In this case, you must set the slaveOk option to true.

• copydb does not snapshot the database. If the state of the database changes at any point during the operation, the resulting database may be inconsistent.

• You must run copydb on the destination server.

• The destination server is not locked for the duration of the copydb operation. This means that copydb will occasionally yield to allow other operations to complete.

• If the remote server has authentication enabled, then you must include a username and password. You must also include a nonce and a key. The nonce is a one-time password that you request from the remote server using the copydbgetnonce command. The key is a hash generated as follows:

  hex_md5(nonce + username + hex_md5(username + ":mongo:" + pass))
  

  If you need to copy a database and authenticate, it’s easiest to use the shell helper:

  db.copyDatabase(<remote_db_name>, <local_db_name>, <from_host_name>, <username>, <password>)