Can't open the mysql.plugin table. Please run mysql

service mysqld start 報錯
090517 13:34:15 [ERROR] Can't open the mysql.plugin table. Please run mysql_upgrade to create it.
090517 13:34:15 [ERROR] Fatal error: Can't open and lock privilege tables: Table 'mysql.host' doesn't exist
090517 13:34:15 mysqld_safe mysqld from pid file /usr/local/mysql/var/mail.bmitwap.com.pid ended
090517 13:38:35 mysqld_safe Starting mysqld daemon with databases from /usr/local/mysql/var

解決辦法 在運行初始化權限表的時候使用增加參數--datadir ，命令格式爲：
shell> scripts/mysql_install_db --user=mysql --datadir=/usr/local/mysql/var
這樣問題就解決了。