Where can I find mysqld error logs?
I have no idea how it happened, but:
1) mysqld was not using /etc/mysql/my.cnf file.

2) I could not find any other my.cnf files on the machine.

3) So i changed /etc/mysql/my.cnf to point to my data files

4) And I created a symlink for socket:

ln -s /var/run/mysqld/mysqld.sock /tmp/mysql.sock

5) And then I run the deamon:

/usr/local/mysql/bin/mysqld_safe --defaults-file=/etc/mysql/my.cnf