mongo-replication-backup

MongoDB Replication Backup and Recovering Steps:

1. When the Mongo-master system gets down, any one of the two mongo-slave machine will become secondary to primary state.

2. Now check whether the mongo service is stopped running in mongo-master machine otherwise stop it.
    
    sudo service mongod stop

3. Now delete the mongoDB path in the mongo-master machine, which is located in /data/db.

    sudo rm -rf /data/db

4. After deleteing the mongoDB path in mongo-master machine, create a new directory named db and give permission to it.

    sudo mkdir /data/db

    sudo chmod 777 /data/db

5. And now start the mongoDB in mongo-master machine.

    sudo service mongod start

6. Now logging into mongoDB using mongo command it will be in startup2 state. 

7. It will automatically recover data from mongo-slave(primary) machine. After sometime the state will change from startup2 to secondary state.

8. Then stop the mongod service in all the machine.

    sudo service mongod stop

9. Finally start the mongod service in Mongo-master and mongo-slaves machines. 

    sudo service mongod start

10. The mongo-master machine becomes primary state and mongo-slave machine becomes secondary state. 

11. Check the recovered database using show dbs command in mongo-master(primary) machine.





Copy MongoDB Database from one instance to another instance.


sudo mongodump --db telecmi --archive | mongorestore --host publicIP --archive --drop