图示：
日志：
190625 10:48:42 InnoDB: Started; log sequence number 0 130207
190625 10:48:42 [ERROR] Fatal error: Can't open and lock privilege tables: Table 'mysql.host' doesn't exist
190625 10:48:42 mysqld_safe mysqld from pid file /var/run/mysqld/mysqld.pid ended
190625 10:48:57 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql
190625 10:48:57 [Warning] /usr/libexec/mysqld: Option '--set-variable' is deprecated. Use --variable-name=value instead.
190625 10:48:58 InnoDB: Initializing buffer pool, size = 8.0M
190625 10:48:58 InnoDB: Completed initialization of buffer pool
InnoDB: The log sequence number in ibdata files does not match
InnoDB: the log sequence number in the ib_logfiles!
190625 10:48:58 InnoDB: Database was not shut down normally!
InnoDB: Starting crash recovery.
InnoDB: Reading tablespace information from the .ibd files...
InnoDB: Restoring possible half-written data pages from the doublewrite
InnoDB: buffer...
190625 10:48:58 InnoDB: Started; log sequence number 0 130207
190625 10:48:58 [ERROR] Fatal error: Can't open and lock privilege tables: Table 'mysql.host' doesn't exist
190625 10:48:58 mysqld_safe mysqld from pid file /var/run/mysqld/mysqld.pid ended
方法：
一个命令搞定，不要在网上去乱抄，没用
cd /etc/
mysql_install_db
如果，我的方法给你解决了难题，请关注本blog
排错：
mysqld --help --verbose
如果配置文件有错，会在这里面报出来。。。