Product : Microsoft, HyperV/2019, DataCenter
Feature : Site Failover, 5, Extensions
Content Owner:  Roman Macek
Summary
Hyper-V Replica (included) , Storage Replica, Azure Site Recovery or 3rd party Fee-Based Add Ons
Details
Disaster recovery capability has been enhanced through the introduction of Hyper-V Replica - an asynchronous replication of virtual machines over a network link from one Hyper-V host at a primary site to another Hyper-V host at a replica site. In the event of failure at the primary site, administrators can manually fail over production virtual machines to the Hyper-V server at the recovery site.
During failover, virtual machines are brought back to a consistent point in time, and they can be accessed by the rest of the network. Minimum interval of replication is 5 minutes (so there is the usual data loss associated with asynchronous replication) .

With WS 2012R2 you can also configure extended replication where the Replica server forwards information about changes that occur on the primary virtual machines to a third server for additional protection. In addition the frequency of replication, which previously was a fixed value, is now configurable. You can also access recovery points for 24 hours. Previous versions had access to recovery points for only 15 hours.

Hyper-V Replica Pros:
- Affordable DR solution (included in Server 2012, no extra licenses required)
- Does not require expensive SAN based replication
- Test Failover without impact on production vims

Cons:
- Manual failover and recovery actions
- Aimed at smaller scale deployments
- no integration with SAN array replication (like vSphere SRM), no synchronous replication

You can of course use (independent of Hyper-V replica) manual array based replication mechanisms to replicate virtual machines on LUN level between sides. This would either be a pretty manual process or requires (fee-based) third party solution with varying levels of integration and complexity.

In Windows Server 2016, we can leverage Storage Replica to replicate block-to-block from one volume to another. Its work for SAN or Storage Spaces (Direct) solution. So you can replicate the volume from one room to another. It can be part of your recovery plan. The replication can be synchronous or asynchronous depending of the latence of the link between both rooms.

Microsoft provides also Azure Site Recovery to replicate VM from one room to Azure or to another room. This technology is based on Hyper-V Replica.