Starting MySQL.. ERROR! The server quit without updating PID file (/var/lib/mysql/hadoop105.pid).解决

cd /var/lib/mysql
cat hadoop105.err // 查看错误信息

[ERROR] Fatal error: Can't open and lock privilege tables: Table 'mysql.host' doesn't exist
[ERROR] Can't open the mysql.plugin table. Please run mysql_upgrade to create it.

错误为重装时数据目录不一致导致，执行下面语句即可解决

 /usr/bin/mysql_install_db --user=mysql --datadir=/var/lib/mysql/