Today’s tip… 

Copy Offloading or ODX is a new functionality in Windows Server 2012 and 2012 R2 that allows files that are stored on a SAN to be copied to other LUNs on the SAN without having be read up to the operating system.  Instead the operating system is issued a token that can thought of as a point-in-time promise of how certain sectors will look.  Windows can either use the token itself or pass it across the network to another Windows installation that is connected to the same SAN.  When the token is turned in to the SAN, the copy is carried out by the SAN and Windows never needs to touch the actual data.

http://technet.microsoft.com/en-us/library/hh831628.aspx