Most probably, you have installed mysql databases as 'mysql' user just like written in INSTALL file. So to start mysql use "mysql" user
PHP Code:
[root@localhost ~]# cd /usr/local/
[root@localhost local]# cd mysql
[root@localhost mysql]# bin/mysqld_safe --user=mysql &
Starting mysqld daemon with databases from /usr/local/mysql/data
Let us know whether it's a 64-bit server you are trying to start mysql on.