MySQL and debian-sys-maint account
If for some reason your debian-sys-maint account is unset in MySQL, during MySQL start you will have connect to server error. You might need to set this account in the MySQL server itself. cat /etc/mysql/debian.cnf to get the password value from the file. Then connect to the DB mysql -u root -p and execute: GRANT ALL PRIVILEGES ON *.* TO 'debian-sys-maint'@'localhost' IDENTIFIED BY 'YOUR_PASSWORD' WITH GRANT OPTION