Why MySQL says the server is not configured as a slave

Is MySQL giving you the error message “ERROR 1200 (HY000): The server is not configured as slave; fix in config file or with CHANGE MASTER TO” when you try to run START SLAVE? There are a few simple troubleshooting steps to take, but I always forget what to do. This article is to help me remember in the future!

  • First, make sure you have run CHANGE MASTER TO and configured the server as a slave. If you’ve done this, you should get some output from SHOW SLAVE STATUS. If so, go to the next step.
  • Next, make sure you have set a server ID on both the master and the slave. Try running SHOW VARIABLES LIKE 'server_id' on both servers. If the value is zero or one, check the configuration file for an explicit setting, because zero or one is often the default value when nothing is specified. I have seen this cause the slave to fail, even in cases where the master’s ID is 1, which ought to work okay but sometimes doesn’t.
  • Finally, make sure your master and slave have different server IDs (on small networks, I usually set the server ID to the last octet in the server’s IP address, because it’s handy and easy to remember). MySQL slaves will refuse to replicate from a master with the same ID.

You should now be able to run START SLAVE and start your slave replicating from the master.

Did I miss anything? Let me know, and I’ll add it!


About The Author

Baron is the founder and CEO of VividCortex. He is the author of High Performance MySQL and many open-source tools for performance analysis, monitoring, and system administration. Baron contributes to various database communities such as Oracle, PostgreSQL, Redis and MongoDB.


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