执行umount 命令的时候出现 device is busy ，有人在使用这块磁盘
umount /dev/sde1
umount: /u01/app/oracle: device is busy
umount: /u01/app/oracle: device is busy
使用fuser 命令查看哪个进程在使用
[root@localhost ~]# fuser -m /u01/app/oracle/
/u01/app/oracle/: 2636c 2694c
[root@localhost ~]# ps aux | grep
root 0.0 0.2 pts/ S : : bash
root 0.0 0.1 pts/ R+ : : grep
kill - 干掉进程
[root@localhost ~]# kill -
[root@localhost ~]# umount /dev/sde1