This article shows through a 10 minutes video how to implement Hyper-V replication automatic failover and load balancing of VMs.
The replication of VMs is synchronous and real-time between two Hyper-V 2012 R2 servers. Only modifications made inside files making up a virtual machine are replicated. Note that SafeKit implements synchronous real-time replication and not the traditional Hyper-V asynchronous replication. This feature is important because with an asynchronous replication, there is data loss on a failover as explained in this article: synchronous replication vs asynhronous replication.
When the Hyper-V server fails, there is an automatic failover of the VM on the other Hyper-V server. And when the failed server is restarted, there is an automatic reintegration of VM files without stopping the VM on the other active Hyper-V server.
Each VM is replicated and automatically restarted independently. Some VMs can run on the first Hyper-V server and are replicated and restarted on the second Hyper-V server. Other VMs can run on the second Hyper-V server and are replicated and restarted on the first Hyper-V server. The load balancing of VMs between the two servers are controlled by the administrator through the SafeKit web console. By clicking on a swap button, the administrator can move a VM from one Hyper-V server to the other.
The solution requires no shared disk and no special Windows configuration. Only 2 Windows 2012 R2 servers or 2 Windows 8.1 machines (both contain Hyper-V) are necessary. The SafeKit software is installed on both of them.
This solution is a customization of a SafeKit mirror module for a Hyper-V VM. The same architecture can be applied to an application like Micorsoft SQL Server or Oracle or other applications with file replication at byte level and application failover in a mirror cluster. Note that by combining high availability at the application level and at the VM level, it is possible to implement Hyper-V synchronous replication and automatic failover between 3 servers.
If you want to implement this demonstration of Hyper-V replication automatic failover and load balancing of VMs, read this article: step-by-step implementation of a Hyper-V cluster 2012 r2 with replication, automatic failover and load balancing.
In 10 minutes, the video shows all the steps to implement replication automatic failover and load balancing of VMs with SafeKit:
Note that SafeKit makes also Hyper-V replication and automatic failover of VM checkpoint and settings.
Note that this solution is limitted to replication and failover of 25 VMs.
If you want to know more about the difference between HA at the application level and HA at the virtual machine level, read the arcticle benefits of VM HA vs Application HA.