Your architecture options for Hyper-V aren’t just limited to a single hosted server or a single site cluster. They won’t cover you for DR.
There’s lots of options out there. If you have huge budget and diskless hosts, you can replicate a SAN from site A to site B across dark fibre. Initiating the DR site is easy. Ensure site A is offline and power up site B. Because the hosts are diskless, they store everything about themselves (operating system, identity, configuration, services and data) on the replicate SAN. As long as the site B hardware is identical you can power it up and carry on working as before.
That sounds perfect, eh? But dark fibre is expensive! You might be able to get away with 1GB copper but that’s really pushing it for SAN replication.
More affordable is host based replication. I just saw that Double-Take has a few solutions. Note that HP customers can get HP rebranded Double-Take software. You can replicate VM’s on a single host to another host using Double-Take for Windows. Or you can use GeoCluster to get much more advanced solutions.
This also reminds me that you can use things like Double-Take or Replistor to do P2V DR of data (not operating systems and applications), e.g. you can have a production physical SQL box called SQL1 and replicate the SQL databases and log files to SQL2 which is an identically configured VM in the DR site.
An interesting way to do is to continually P2V your machine using an imaging solution that can handle drivers. Acronis have a great reputation for driver substitution in their imaging solutions. Their True Image Echo Enterprise Server solution allows continual P2V of physical machines to virtualised DR machines. Invocation is a restoration of your stored images, something you can regularly test in Hyper-V with private networks. That Acronis product supports lots of operating systems. There’s a cheaper version for Windows.