mysql启动失败：Job for mysqld.service failed because the control process exited with error code.

[root@localhost mysql]# systemctl start mysqld
Job for mysqld.service failed because the control process exited with error code. See "systemctl status mysqld.service" and "journalctl -xe" for details.

哼，这种情况不要去纠结pid的问题，直接去找错误日志文件

我的找了半天，在/usr/local/mysql/data/localhost.localdomain.err 这里面

cat /usr/local/mysql/data/localhost.localdomain.err 

嗯，看不懂，问ai

sudo chown -R mysql:mysql /usr/local/mysql/data/  
sudo chmod 755 /usr/local/mysql/data/

再次重启，搞定！