Hello,   It *should* work, but sounds like maybe cluster services is preventing the OS from reading the new capacity.  Might take a failover or even rebooting the cluster nodes to get it to see the new space.  If you have support from MS, it would be worth a call to them as well. 
Hi, I  have increased volume size in Dell EqualLogic Group Manager (GUI). On windows I see that volume capacity is 200 but it does not allow to increase the size to 200gb. After scanning disk total size shows as only 100 and size no any unallocated space available. Is this windows 2012 bug ? not sure where to start troubleshooting. Connection to server cluster is through iSCSI.  I see unreserved space on EqualLogic, but not in windows, thanks
Unable increase volume size from windows