umount: /***: device is busy.

Sometimes when you try to umount a device you end up with error " umount: /***: device is busy ", 

e.g.

# umount /***

umount: /***: device is busy.
(In some cases useful info about processes that use
the device is found by lsof(8) or fuser(1))

Fix 1: It means that some process has a working directory or an open file handle underneath the mount point. The best thing to do is to end the offending process, change its working directory or close the file handle before unmounting.

Fix 2: There is an alternative on Linux though. Using umount -l calls a "lazy" unmount. The filesystem will still be mounted but you won't be able to see or use it, except for processes that are already using it. When the offending program exits (through whatever means) the system will "finish" unmounting the filesystem.

# umount -l /***

 This wil FIX it........