Yesterday Microsoft released the first public beta of the next version of Windows Home Server, currently going under the codename of Vail (or as we like to call it, WHS v2). WHS v2 has been something of a poorly kept secret, as word leaked out about its development as early as 2008. In more recent times an internal beta leaked out late last year, confirming that WHS v2 existed and giving everyone an idea of what Microsoft has in store for the next iteration of their fledgling home server OS.

One thing in particular caught our eye about the WHS v2 beta: the new Drive Extender. Drive Extender is the secret sauce of Windows Home Server that gives it its storage pool and data redundancy features, and now Microsoft has rearchitected it for WHS v2. We'll take a look at just what they did, why it's going to be more compatible and fault-tolerant than WHS v1's Drive Extender was, what the costs of all of this are, and why we think it's a great deal like Sun's popular next-generation ZFS file system.