In an earlier post by me I described how to get open-vm-tools working in Ubuntu 9.10. Turns out that this doesn’t quite work for the latest version of Ubuntu, 10.04. A few tickets were spent on it at Launchpad and finally last night someone, I presume the module author, said you also need to install open-vm-dkms. Which I did. After this the module vmhgfs is available again and can be loaded.
So, when you install open-vm-tools and you want to make use of the vmhgfs driver you need to install open-vm-dkms. Otherwise compiling it yourself with m-a will fail. Note that with this step you no longer need to compile it yourself, as apt-get does it for you.
sudo apt-get install open-vm-tools open-vm-dkms