[ERROR] Fatal error: Can’t open and lock privilege tables: Table ‘mysql.user’ doesn’t exist

This error ocurs then the database mysql is missing or corrupt.
Stop the mysql server “service mysql-server stop”
Make a backup of /var/db/mysql “mv /var/db/mysql /var/db/mysql.old”.
To rebuild the database execute “/usr/local/libexec/mysqld –initialize”
You will get a temporary password. Remember the password for later use.
Start the mysql server “service mysql-server start”
To start upp the new configuration “mysql_secure_installation”. Use the Password to start the configuration and step thru the wizzard.
Restore the mysql backup and the server is good as new.