# REPLICAOF The `REPLICAOF` command can change the replication settings of a replica on the fly. If a Redis server is already acting as replica, the command `REPLICAOF` NO ONE will turn off the replication, turning the Redis server into a MASTER. In the proper form `REPLICAOF` hostname port will make the server a replica of another server listening at the specified hostname and port. If a server is already a replica of some master, `REPLICAOF` hostname port will stop the replication against the old server and start the synchronization against the new one, discarding the old dataset. The form `REPLICAOF` NO ONE will stop replication, turning the server into a MASTER, but will not discard the already replicated data. So, if the old master stops working, it is possible to turn the replica into a master and set the application to use this new master in read/write. Later when the other Redis server is fixed, it can be reconfigured to work as a replica. ## Examples ``` > REPLICAOF NO ONE "OK" > REPLICAOF 127.0.0.1 6799 "OK" ``` ## Return information {{< multitabs id="replicaof-return-info" tab1="RESP2" tab2="RESP3" >}} [Simple string reply](../../develop/reference/protocol-spec#simple-strings): `OK`. -tab-sep- [Simple string reply](../../develop/reference/protocol-spec#simple-strings): `OK`.