how to use CLUSCTL_RESOURCE_TYPE_STORAGE_GET_DISKID

The documentation is NOT very clear on how to implement "CLUSCTL_RESOURCE_TYPE_STORAGE_GET_DISKID" & "CLUSCTL_RESOURCE_TYPE_STORAGE_IS_CLUSTERABLE"

I am reading the following link : http://msdn.microsoft.com/en-us/library/cc225286.aspx

How to fill the lpOutBuffer is unclear. 

Any samples and advice will be appreciated.

PS: I am asking about the "server" side implementation.