Testing the Server the permissions for the involved files and directories so that the server has the right to use them. You can also start the server as  root , but this raises security issues and should be avoided. Change location to the data directory and check the ownership of the data directory and its contents to make sure the server has access. For example, if the data directory is  /usr/local/mysql/var , use this command: shell>  ls -la /usr/local/mysql/var If the data directory or its files or subdirectories are not owned by the login account that you use for running the server, change their ownership to that account. If the account is named  mysql , use these commands: shell>  chown -R mysql /usr/local/mysql/var shell>  chgrp -R mysql /usr/local/mysql/var Even with correct ownership, MySQL might fail to start up if there is other security software running on your system that manages application access to various parts of the file system. In this case, reconfigure that software to enable  mysqld  to access the directories it uses during normal operation. If either of the following errors occur, it means that some other program (perhaps another  mysqld server) is using the TCP/IP port or Unix socket file that  mysqld  is trying to use: Can’t start server: Bind on TCP/IP port: Address already in use Can’t start server: Bind on unix socket... Use  ps  to determine whether you have another  mysqld  server running. If so, shut down the server before starting  mysqld  again. (If another server is running, and you really want to run multiple servers, you can find information about how to do so in Section 5.8, “Running Multiple MySQL Instances on One Machine” .) If no other server is running, execute the command  telnet  your_host_name tcp_ip_port_number . (The default MySQL port number is 3306.) Then press Enter a couple of times. If you do not get an error message like  telnet: Unable to connect to remote host: Connection refused , some other program is using the TCP/IP port that  mysqld  is trying to use. Track down what program this is and disable it, or tell  mysqld  to listen to a different port with the  -- port  option. In this case, specify the same non-default port number for client programs when connecting to the server using TCP/IP. Another reason the port might be inaccessible is that you have a firewall running that blocks connections to it. If so, modify the firewall settings to permit access to the port. If the server starts but you cannot connect to it, make sure that you have an entry in  /etc/hosts  that looks like this: 127.0.0.1 localhost After the data directory is initialized and you have started the server, perform some simple tests to make sure that it works satisfactorily. This section assumes that your current location is the MySQL installation directory and that it has a  bin  subdirectory containing the MySQL programs used here. If that is not true, adjust the command path names accordingly. 256 2.10.3 Testing the Server •If you cannot get  mysqld  to start, try to make a trace file to find the problem by using the  --debug option. See Section 5.9.4, “The DBUG Package” . •Verify that the network interfaces the server wants to use are available.