Sorry for my English;

I was trying to create db with rake in RoR application that has been configured for MySQL(gem installed, settings changed).
After that attempt mysql-server broke:
d@calister:~$ mysql
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)

mysqld is not running at all:
d@calister:~$ ps aux | grep mysql
d 3769 0.0 0.0 4368 832 pts/0 S+ 18:03 0:00 grep --color=auto mysql

And also it doesn't seem it would like to run:
d@calister:~$ sudo service mysql start
start: Job failed to start

Any suggestions?
Thanks

EDIT:

d@calister:~$ sudo -u mysql mysqld
120520 18:45:11 [Note] Plugin 'FEDERATED' is disabled.
mysqld: Table 'mysql.plugin' doesn't exist
120520 18:45:11 [ERROR] Can't open the mysql.plugin table. Please run mysql_upgrade to create it.
120520 18:45:11 InnoDB: The InnoDB memory heap is disabled
120520 18:45:11 InnoDB: Mutexes and rw_locks use GCC atomic builtins
120520 18:45:11 InnoDB: Compressed tables use zlib 1.2.3.4
120520 18:45:11 InnoDB: Initializing buffer pool, size = 128.0M
120520 18:45:11 InnoDB: Completed initialization of buffer pool
120520 18:45:11 InnoDB: highest supported file format is Barracuda.
120520 18:45:12  InnoDB: Waiting for the background threads to start
120520 18:45:13 InnoDB: 1.1.8 started; log sequence number 1589459
120520 18:45:13 [ERROR] Fatal error: Can't open and lock privilege tables: Table 'mysql.host' doesn't exist