Dear Gurus

I am a bit confused as to the role of OCFS in RAC on Windows. My understanding of OCFS is that it is Oracle's own file system implemented in Windows to allow disk sharing between the cluster nodes. If this is correct, can some one tell me:

1) What the role of OCFS is on RAC on Windows?

2) If raw devices will still be needed to be configured on Windows RAC cluster even when OCFS is implemented?

3) Why we still need raw devices on Windows with OCFS when the OCFS software is meant to allow disk sharing?

4)Any other good reading material on this apart from Oracle docs?