MySQL on Debian versions is configured differently than the native local MySQL plugin so you will be disappointed when your password on the mysql client fails by default.
Here is how you reset the MySQL root password the proper and "working way"
#first we gracefully stop mysql
sudo systemctl stop mysql;
#then we forcefully kill any mysqld process just in case
sudo killall -9 mysqld mysqld_safe;........
mysql reset root password.
Oops I can't remember my MySQL root password!
[root@centos7test etc]# mysql -u root -p
Enter password:
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)
First we need to stop mariadb:
systemctl stop mariadb
Now we need to restart it with skip-grant-tables whic........
One note is to secure MySQL, I don't know for sure but I believe you could login to MySQL remotely with no password during this operation (I'm not sure, maybe it doesn't accept blank passwords but I firewall MySQL port anyway and recommend you do the same).
First edit /etc/my.cf
Under the [mysqld] field add the following line somewhere:
skip-grant-tables
Now restart mysql: service mysql restart or on Debian sty........