fix:
sudo ln -f -s /opt/VBoxGuestAdditions-5.1.20/lib/VBoxGuestAdditions/mount.vboxsf /sbin/mount.vboxsf
sudo mount -t vboxsf WinShare /mnt/Share
from:
https://forums.virtualbox.org/viewtopic.php?f=3&p=283645
自动挂载:
sudo nano /etc/rc.local
增加:mount -t vboxsf WinShare /mnt/Share/