Linux MYSQL:dead but pid file exists

MYSQL dead but pid file exists问题 - CSDN博客
https://blog.csdn.net/shilian_h/article/details/38020567

Error "mysqld dead but pid file exists" - Stack Overflow
https://stackoverflow.com/questions/24831119/error-mysqld-dead-but-pid-file-exists

mysqld dead but pid file exists - CSDN博客
https://blog.csdn.net/zhoujj303030/article/details/44455165

方案一亲测有效，方案二三应该也可以（未测）。