Device or Resource Busy
An attempt to access or modify something failed as it is already in use. Probably the most common reason for seeing this is trying to unmount a disk partition while processes have open file descriptors on that device.
(your shell now using the floppy disk)
$ umount /floppy umount /floppy: device is busy
If you want to find out why a disk is busy
fuser -vm /floppy
will list the processes that are using that disk :)
8 pages link to EBUSY:
lib/plugin/WlugLicense.php:99: Warning: Invalid argument supplied for foreach()
lib/plugin/WlugLicense.php:111: Warning: in_array() [<a href='function.in-array'>function.in-array</a>]: Wrong datatype for second argument