如果一个文件系统打开了一个文件，那么必须在卸载之前将该文件关闭。例如：
# umount /home
umount: 0506-349 Cannot unmount /dev/hd1: The requested resource is busy.
如果显示umount busy

用如下命令
# fuser -x -c /home
/home: 11630
# ps -ef|grep 11630
UID PID PPID C STIME TTY TIME CMD
guest 11630 14992 0 16:44:51 pts/1 0:00 -sh
# kill -1 11630
# umount /home