之前创建了一个普通用户prize，现在想删掉它：
[root@VM_0_14_centos /]# userdel prize userdel: user prize is currently used by process 28021
发现原来我克隆了一个会话，另一个窗口还登陆着该用户prize呢，关掉就好了，如果我们还要重新创建该用户，记得先删干净原来的东西：
[root@centos /]# userdel prize [root@centos /]# find / -name prize /var/spool/mail/prize /var/lib/mysql/prize /home/prize [root@centos /]# rm -rf /var/spool/mail/prize /var/lib/mysql/prize /home/prize [root@centos /]# find / -name prize [root@centos /]# useradd prize