执行mysqld_safe报错：
[root@edu data]# /usr/local/mysql5.7/bin/mysqld_safe --user=mysql
160427 12:41:28 mysqld_safe Logging to '/renqinglei/mysql/log/mysql_error.log'.
160427 12:41:28 mysqld_safe The file /usr/local/mysql/bin/mysqld
does not exist or is not executable. Please cd to the mysql installation
directory and restart this script from there as follows:
./bin/mysqld_safe&
See http://dev.mysql.com/doc/mysql/en/mysqld-safe.html for more information
后台错误日志报：
160427 12:41:28 mysqld_safe The file /usr/local/mysql/bin/mysqld
does not exist or is not executable. Please cd to the mysql installation
directory and restart this script from there as follows:
./bin/mysqld_safe&
See http://dev.mysql.com/doc/mysql/en/mysqld-safe.html for more information
根据网上所说重新初始化数据库也不好使，
依据 惜分飞文章：mysqld_safe启动报错 mysqld_safe只认识/usr/local/mysql/bin/mysqld路径的mysqld
于是调整在当前目录创建了一个软链接，问题解决。
[root@edu local]# ln -s mysql5.7/ mysql
记录此错，仅为以后提醒。