DRBD is a protocol for mirroring the storage on one server with the storage on another. Essentially it gives you a highly available (HA) cluster of storage across two or more physical machines, without the need for an expensive SAN.
It seems this kind of setup is possible in Linux, but I use Windows 2012 and Hyper V to host my virtual machines, some of which are Win 2012, some of which are Linux.
Put simply - is it possible to either create a DRBD setup on a Windows machine - I've seen the Starwind app but they want silly money for it - you may as well buy a SAN? Alternatively is it possible to create a DRBD share on 2 Linux boxes, and then use that storage for cluster Hyper V storage? Can a DRBD share on Linux present itself as an iSCSI target / SMB 3 volume?