Product : Microsoft, HyperV/2019, DataCenter
Feature : Replication / Site Failover, HA/DR, VM Mobility and HA
Content Owner:  Roman Macek
Hyper-V Replica - Storage Replica
(No major change in WS2019)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

- 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.

With Windows Server 2016, you can now replicate at the level block your CSV volume from one cluster to another, from one server to another or between volumes. Thanks to Storage Replica, you can replicate your volumes from one room to another to ensure the Disaster Recovery. When a disaster occurs, you just have to remove the replication link and the volume in the second room is available in read/write. You just have to start your VM