mysql运行时报错，“Can't open the mysql.plugin table”

/httx/run/mysql/bin/mysqld: Can't find file: './mysql/plugin.frm' (errno: 13 - Permission denied)
2017-06-30 16:04:49 7571 [ERROR] Can't open the mysql.plugin table. Please run mysql_upgrade to create it.
2017-06-30 16:04:49 7571 [Note] InnoDB: Using atomics to ref count buffer pool pages
2017-06-30 16:04:49 7571 [Note] InnoDB: The InnoDB memory heap is disabled
2017-06-30 16:04:49 7571 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2017-06-30 16:04:49 7571 [Note] InnoDB: Memory barrier is not used
2017-06-30 16:04:49 7571 [Note] InnoDB: Compressed tables use zlib 1.2.3
2017-06-30 16:04:49 7571 [Note] InnoDB: Using Linux native AIO
2017-06-30 16:04:49 7571 [Note] InnoDB: Not using CPU crc32 instructions
2017-06-30 16:04:49 7571 [Note] InnoDB: Initializing buffer pool, size = 128.0M
2017-06-30 16:04:49 7571 [Note] InnoDB: Completed initialization of buffer pool
2017-06-30 16:04:49 7571 [Note] InnoDB: Highest supported file format is Barracuda.
2017-06-30 16:04:49 7f2c2f2ab720 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.
2017-06-30 16:04:49 7571 [ERROR] InnoDB: Could not find a valid tablespace file for 'mysql/innodb_index_stats'. See http://dev.mysql.com/doc/refman/5.6/en/innodb-troubleshooting-datadict.html for how to resolve the issue.
2017-06-30 16:04:49 7571 [ERROR] InnoDB: Tablespace open failed for '"mysql"."innodb_index_stats"', ignored.
2017-06-30 16:04:49 7f2c2f2ab720 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.
2017-06-30 16:04:49 7571 [ERROR] InnoDB: Could not find a valid tablespace file for 'mysql/innodb_table_stats'. See http://dev.mysql.com/doc/refman/5.6/en/innodb-troubleshooting-datadict.html for how to resolve the issue.
2017-06-30 16:04:49 7571 [ERROR] InnoDB: Tablespace open failed for '"mysql"."innodb_table_stats"', ignored.
2017-06-30 16:04:49 7f2c2f2ab720 InnoDB: Operating system error number 13 in a file operation.
InnoDB: The error means mysqld does not have the access rights to

解决方法是：在运行初始化权限表的时候使用增加参数--datadir ，命令格式为： shell> ..../mysql_install_db --user=mysql --datadir=/usr/local/mysql/var