A Management Node fails to start with the error "ERROR 2002: Can't connect to MySQL server." How do I resolve this?

Symptom

The Management Node fails to start with the error: ERROR 2002: Can't connect to MySQL server.

Cause

The Management Node database is in an abnormal state with the error: service changed on disk.

Solution

1. Log in to the Management Node and run the following command to reload the configuration file:

   systemctl daemon-reload

2. Run the following command to restart the database service:

   systemctl restart mariadb

3. Run the following command to start the Management Node:

   zstack-ctl start