Quick answer: To reset a lost MySQL root password, stop the database, start it in a mode that skips permission checks, set a new password, then restart normally. On modern MySQL and MariaDB the cleanest method is the init-file approach. You need root or sudo access to the server.
Create a file, for example /tmp/reset.sql, with the new password:
ALTER USER 'root'@'localhost' IDENTIFIED BY 'NewStrongPass123!';
Stop the service, then start it pointing at that file:
systemctl stop mysqld mysqld --init-file=/tmp/reset.sql &
Once it starts, stop it, restart the service normally, and delete the file. On MariaDB use FLUSH PRIVILEGES; SET PASSWORD ... syntax if ALTER USER is unavailable.
Stopping the service and starting with --skip-grant-tables lets you connect without a password to set a new one. Because this disables authentication, allow no external connections while it is running, and re-enable grants immediately after.
Is this safe on a live server?
Both methods briefly interrupt the database. Do it during a maintenance window and never leave skip-grant-tables running with the port exposed.
What if I only lost the application user password?
Log in as root and run ALTER USER for that account - no restart needed.
On a SoftSys managed Linux VPS our team can safely reset database credentials for you without risking downtime.
