I have reinstalled my system to Ubuntu 12.04, after installed mysql, i found that there is an error when start mysql: 

Access denied 

for user ‘debian-sys-maint’@'localhost’ (using password: YES) 

 

After searching the reason via google, i at last found the reason, here is it:

That’s because debian has a mysql account 

for switching on/off and checking mysql status, and mysql password 

for that user “debian-sys-maint” should be the same stored 

in /etc/mysql/debian.cnf

 

here is the way to resolve it.

1. check the password in /etc/mysql/debian.cnf

sudo vim /etc/mysql/debian.cnf

you will see something like these:

[client]

host     = localhost

user     = debian-sys-maint

password = your-password-here

socket   = /var/run/mysqld/mysqld.sock

[mysql_upgrade]

host     = localhost

user     = debian-sys-maint

password = your-password-here

socket   = /var/run/mysqld/mysqld.sock

basedir  = /usr 

 

2. login to mysql:

mysql -u root -p

 

3. grant the rights to debian-sys-maint

mysql> GRANT ALL PRIVILEGES ON *.* TO ‘debian-sys-maint’@'localhost’ IDENTIFIED BY ‘your-password-here’ WITH GRANT OPTION;

 

Query OK, 0 rows affected (0.00 sec) 

 

Done!