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MySQL - Resetting a lost MySQL root password
The MySQL root password allows full access to the MySQL database and allows for all actions to be undertaken including creating new users, new databases, setting access rules and so on.
Losing one can be a difficult issue to encounter. Luckily, resetting the root password is easy as long as you have sudo access to the Server.
Contents
Not the Server root user
A common issue is confusing the Server root user with the MySQL root user.
The Server root user is the server's main user. The MySQL root user has complete control over MySQL only. The two 'root' users are not connected in any way.
Stop MySQL
The first thing to do is stop MySQL. If you are using Ubuntu or Debian the command is as follows:
sudo /etc/init.d/mysql stop
For CentOS, Fedora, and RHEL the command is:
sudo /etc/init.d/mysqld stop
Safe mode
Next we need to start MySQL in safe mode - that is to say, we will start MySQL but skip the user privileges table. Again, note that you will need to have sudo access for these commands so you don't need to worry about any user being able to reset the MySQL root password:
sudo mysqld_safe --skip-grant-tables &
Note: The ampersand (&) at the end of the command is required.
Login
All we need to do now is to log into MySQL and set the password.
mysql -u root
Note: No password is required at this stage as when we started MySQL we skipped the user privileges table.
Next, instruct MySQL which database to use:
use mysql;
Reset Password
Enter the new password for the root user as follows:
update user set password=PASSWORD("mynewpassword") where User='root';
and finally, flush the privileges:
flush privileges;
Restart
Now the password has been reset, we need to restart MySQL by logging out:
quit
and simply stopping and starting MySQL.
On Ubuntu and Debian:
sudo /etc/init.d/mysql stop
...
sudo /etc/init.d/mysql start
On CentOS and Fedora and RHEL:
sudo /etc/init.d/mysqld stop
...
sudo /etc/init.d/mysql start
Login
Test the new password by logging in:
mysql -u root -p You will be prompted for your new password.