虚拟Ubuntu共享主机文件问题

安装好Virtual Box虚拟机的32位Ubuntu10.10 Alpha 1并分配共享数据空间后，
w@w-desktop:~$ sudo mkdir /mnt/fpan
[sudo] password for wsk:
w@w-desktop:~$ sudo mkdir /mnt/mdowns
w@w-desktop:~$ sudo mount -t vboxsf 72E1-F60E /mnt/fpan
mount: 未知的文件系统 `vboxsf'
w@w-desktop:~$ sudo umount -f /mnt/fpan
umount2: 无效的参数
umount: /mnt/fpan 未挂载
w@w-desktop:~$ sudo mount -t msdos 72E1-F60E /mnt/fpan
mount: 特殊设备 72E1-F60E 不存在
w@w-desktop:~$ sudo mount -t fat 72E1-F60E /mnt/fpan
mount: 未知的文件系统 `fat'
w@w-desktop:~$ sudo mount -t fat32 72E1-F60E /mnt/fpan
mount: 未知的文件系统 `fat32'
w@w-desktop:~$ sudo mount -t 72E1-F60E /mnt/fpan
Usage: mount -V : print version
mount -h : print this help
mount : list mounted filesystems
mount -l : idem, including volume labels
So far the informational part. Next the mounting.
The command is `mount [-t fstype] something somewhere'.
Details found in /etc/fstab may be omitted.
mount -a [-t|-O] ... : mount all stuff from /etc/fstab
mount device : mount device at the known place
mount directory : mount known device here
mount -t type dev dir : ordinary mount command
Note that one does not really mount a device, one mounts
a filesystem (of the given type) found on the device.
One can also mount an already visible directory tree elsewhere:
mount --bind olddir newdir
or move a subtree:
mount --move olddir newdir
One can change the type of mount containing the directory dir:
mount --make-shared dir
mount --make-slave dir
mount --make-private dir
mount --make-unbindable dir
One can change the type of all the mounts in a mount subtree
containing the directory dir:
mount --make-rshared dir
mount --make-rslave dir
mount --make-rprivate dir
mount --make-runbindable dir
A device can be given by name, say /dev/hda1 or /dev/cdrom,
or by label, using -L label or by uuid, using -U uuid .
Other options: [-nfFrsvw] [-o options] [-p passwdfd].
For many more details, say man 8 mount .
w@w-desktop:~$ sudo mount -t MDouns /mnt/mdouns
Usage: mount -V : print version
mount -h : print this help
mount : list mounted filesystems
mount -l : idem, including volume labels
So far the informational part. Next the mounting.
The command is `mount [-t fstype] something somewhere'.
Details found in /etc/fstab may be omitted.
mount -a [-t|-O] ... : mount all stuff from /etc/fstab
mount device : mount device at the known place
mount directory : mount known device here
mount -t type dev dir : ordinary mount command
Note that one does not really mount a device, one mounts
a filesystem (of the given type) found on the device.
One can also mount an already visible directory tree elsewhere:
mount --bind olddir newdir
or move a subtree:
mount --move olddir newdir
One can change the type of mount containing the directory dir:
mount --make-shared dir
mount --make-slave dir
mount --make-private dir
mount --make-unbindable dir
One can change the type of all the mounts in a mount subtree
containing the directory dir:
mount --make-rshared dir
mount --make-rslave dir
mount --make-rprivate dir
mount --make-runbindable dir
A device can be given by name, say /dev/hda1 or /dev/cdrom,
or by label, using -L label or by uuid, using -U uuid .
Other options: [-nfFrsvw] [-o options] [-p passwdfd].
For many more details, say man 8 mount .
w@w-desktop:~$
然而打开/mnt/mdowns等文件夹却全是空的，明明主机里面的有文件啊。请各位朋友相助