usr/sbin/mysqld: Can't find file: './mysql/plugin.frm' (errno: 13)
150706 22:48:33 [ERROR] Can't open the mysql.plugin table. Please run mysql_upgrade to create it.
150706 22:48:33 InnoDB: The InnoDB memory heap is disabled
150706 22:48:33 InnoDB: Mutexes and rw_locks use GCC atomic builtins
150706 22:48:33 InnoDB: Compressed tables use zlib 1.2.3.4
150706 22:48:33 InnoDB: Initializing buffer pool, size = 128.0M
150706 22:48:33 InnoDB: Completed initialization of buffer pool
150706 22:48:33  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.