Can not login to mysql 5.7.9 after change password

Question

I have installed Mysql Ver 14.14 Distrib 5.7.9, for Linux (x86_64) using EditLine wrapper On CentOS Linux release 7.1.1503

I Chang

Answer 1

Two things have changed since earlier versions of mySQL (I''m using 5.7.10):

1. systemd is now used to look after mySQL instead of mysqld_safe (which is why I was getting the -bash: mysqld_safe: command not found error - it's not installed)

2. The user table structure has changed.

So to reset the root password, you still start mySQL with --skip-grant-tables options and update the user table, but how you do it has changed.

1. Stop mysql:
systemctl stop mysqld

2. Set the mySQL environment option 
systemctl set-environment MYSQLD_OPTS="--skip-grant-tables"

3. Start mysql usig the options you just set
systemctl start mysqld

4. Login as root
mysql -u root

5. Update the root user password with these mysql commands
mysql> UPDATE mysql.user SET authentication_string = PASSWORD('MyNewPassword')
    -> WHERE User = 'root' AND Host = 'localhost';
mysql> FLUSH PRIVILEGES;
mysql> quit

6. Stop mysql
systemctl stop mysqld

7. Unset the mySQL envitroment option so it starts normally next time
systemctl unset-environment MYSQLD_OPTS

8. Start mysql normally:
systemctl start mysqld

Try to login using your new password:
7. mysql -u root -p

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Reference

As it says at http://dev.mysql.com/doc/refman/5.7/en/mysqld-safe.html,

Note

As of MySQL 5.7.6, for MySQL installation using an RPM distribution, server startup and shutdown is managed by systemd on several Linux platforms. On these platforms, mysqld_safe is no longer installed because it is unnecessary. For more information, see Section 2.5.10, “Managing MySQL Server with systemd”.

Which takes you to http://dev.mysql.com/doc/refman/5.7/en/server-management-using-systemd.html where it mentions the systemctl set-environment MYSQLD_OPTS= towards the bottom of the page.

The password reset commands are at the bottom of http://dev.mysql.com/doc/refman/5.7/en/resetting-permissions.html