In MySQL 5.5.13, after writing default-character-set=utf8, I couldn’t start it anymore.

The cause was that the server-side character code notation had changed from MySQL 5.5, but I was using the old syntax.

# service mysqld restart
Stopping mysqld:                                           [  OK  ]
MySQL Daemon failed to start.
Starting mysqld:                                           [FAILED]

There was an article with a solution, so I’ll quote it. The new character code setting should be written as character-set-server.

It seems the cause was that I had written the following in my.cnf:

[mysqld]
default-character-set=utf8
[mysql]
default-character-set=utf8

The client mysql side setting is fine, but the server side notation changed from mysql5.5. The new syntax is:

[mysqld]
character-set-server=utf8
[mysql]
default-character-set=utf8

Source: fedora15 mysql5.5 can’t start due to default-character-set - Let’s Live with IT

That’s all from the Gemba.