在ubuntu10.10 修改mysql data的默认路径后mysql服务启动失败



在ubuntu10.10 修改mysql data的默认路径后mysql服务启动失败
错误日志：
111206 17:29:35 [Note] Plugin 'FEDERATED' is disabled.
/usr/sbin/mysqld: Can't find file: './mysql/plugin.frm' (errno: 13)/usr/sbin/mysqld: Can't find file: './mysql/plugin.frm' (errno: 13)
111206 17:29:35 [ERROR] Can't open the mysql.plugin table. Please run mysql_upgrade to create it.
111206 17:29:35  InnoDB: Operating system error number 13 in a file operation.
InnoDB: The error means mysqld does not have the access rights to
InnoDB: the directory.
InnoDB: File name ./ibdata1
InnoDB: File operation call: 'open'.
InnoDB: Cannot continue operation.
InnoDB: File operation call: 'open'.
修改下面文件：
/etc/apparmor.d/usr.sbin.mysqld
原来：
  /var/lib/mysql/ r,
  /var/lib/mysql/** rwk,
修改后：
  /host/mysql/ r,   
  /host/mysql/** rwk,