MySQL could not start the reboot unexpectedly because the Linux hostname was changed

MySQL cannot be restarted, cannot be shut down, cannot be started, unusable, if it is because the hostname has been modified, this can be resolved: Shut down all MySQL processes, and then start some mysql!

Today nothing to see their host name is wrong, and then changed to distinguish the server, that only restart MySQL when the following error occurred:

MySQL Manager or server PID file could not being found! [FAILED]
Starting mysql.manager of Pid-file quit without updatingfi[failed]

How can not find the PID, see below:

[[Email protected] ~]# PS aux | Grepmysql
MySQL 16433 0.0 0.2 36636 5756? Sl 15:07 0:00/usr/local/mysql/libexec/mysqld--basedir=/usr/local/mysql--datadir=/usr/local/mysql/var--user= mysql--log-error=/usr/local/mysql/var/hao9goandsecondweb.err--pid-file=/usr/local/mysql/var/ Hao9goandsecondweb.pid--socket=/tmp/mysql.sock--port=3306
Root 16992 0.0 0.0 4020 704pts/0 s+ 15:11 0:00 grep mysql

The original PID or the original hostname. PID, running:

Kill-9 <mysqlpid> then servicemysql start haha see the green OK,

[[Email protected] ~]# service MySQL start
Startingmysql. [ OK]

MySQL could not start the reboot unexpectedly because the Linux hostname was changed