The my.cnf problem

[Jiang HaiZhong]

Hi,All
I have installed the mysql in the linux,
and i wanna do the Sync configuration,
so i just add the the three master info to the
[mysqld] node

[mysqld]
server-id=1
log-bin=/var/mysqlback
binlog-do-db=test

then restart the mysql, it always failed when start the mysql
the error msg is:
Timeout error occurred trying to start Mysql

and the problems is in the 'log-bin=/var/mysqlback' info,
because if i delete that info, it is okay to start the mysql

so what's the problem?

Best Regards
Nicholas