What is Hyper-V Replica and How to Set It up (Step by Step)

What is Hyper-V replica

Hyper-V replica is a free tool first introduced in Windows Server 2012. It is used for fast disaster recovery when error occurs. It works to create a duplicate of the primary virtual machine and transfers data to the secondary server in the same site or different sites. So, you are able to use the copy to restore your original virtual machine in a short time.

Benefits of Hyper-V replica

Creating Hyper-V replica helps to recover the data quickly, provides workload resiliency and reduces the storage cost.

• Fast disaster recovery: When unpredictable events happen to the primary server, disaster recovery can be achieved quickly from the secondary server with less downtime. It keeps business security and reduces financial losses. Creating Hyper-V replica contributes to  data recovery.
• Reduced cost: Hyper-V replication costs less since it is a free tool in Microsoft and replicates VMs to another server which do not rely on the storage systems.
• Scalability: Deploying it with the Azure Site Recovery service so as to achieve automagical replication and extensive scales. When integrated with this service, it is possible to perform replication between local sites or between local sites and Azure.
• Flexibility: It offers workload flexibility for small and medium-sized businesses by replicating between branch offices or regional sites in different geographic locations.

Prerequisites for set up Hyper-V replica

If you want to replicate a virtual machine in Hyper-V, please prepare at least 2 hosts and connect them. To configure Hyper-V replication, you need to provide correct permission as following, otherwise the replication may fail.

1. The primary server and secondary server must have sufficient storage space and physical memory to ensure successful operation of the virtual machines’ replication.

2. Properly configure the firewall to allow traffic to pass through, and enable replication feature between the primary and secondary server (creating HTTP or HTTPS).

3. Confirm network settings to allow proper communication between the primary and secondary server.

How to set up Hyper-V replica step by step

Setting up Hyper-V replica allows you to create a complete duplicate of the source virtual machine without any cost. Setting up Hyper-V replication enables to run failover task and protect your virtual machines well.

When talking about configuration of Hyper-V, you need to know how it works.

Hyper-V failover is included in Windows Server 2012 first which aims to cope with planned and unplanned failover situations which is very effective for disaster recovery.

◈Planned Failover: When a scheduled event happens in the primary host server, you can switch the failover to the replica server.

◈Unplanned Failover: When an unpredictable event happens in the primary site such as unexpected power outage, a natural disaster or virus attack, you can use failover to protect your virtual machines.

The following part will introduce you the detailed steps on how to configure Hyper-V replication in Windows Server 2016.

Steps to set up Hyper-V replica

If you want to configure Hyper-V replica, you should make sure to set up Hyper-V hosts and firewall successfully, then go to enable the virtual machine replication.

Step 1. Set up Hyper-V hosts

1. Before you start setup, please ensure you have as least 2 host servers.

2. Right click the VM, and select Hyper-V Setting >> Replication Configuration >> Enable this computer as a Replica server.1. Before you start setup, please ensure you have as least 2 host servers.

3. Specify the authentication types (HTTP or HTTPS) to let the incoming replication traffic go through.

◈Use Kerberos (HTTP): If you choose HTTP, the data is not encrypted while connecting, and the data is sent over port 80.

◈Use certificate-based Authentication (HTTPS): If you choose HTTPS, the data is encrypted before sending and it is sent over port 443, and it requires that you should have a SSL certificate signed by a CA.

You can choose the authentication type according to your need. Generally, HTTPs is more secure and recommended.

4. Click Allow replication from any authentication server and select the location to store the replication files.

5. Click Apply to finish settings.

When you finish these steps, an information window may pop up which reminds you to set up the firewall, please go to configure your firewall to allow traffic income, otherwise the replica between the primary and secondary servers will not be admitted.

Step 2. Set up firewall

Here, please follow the steps to set up firewall for traffic income.

1. Go to Control Panel >> Windows Firewall >> Advanced settings >> Inbound Rules.

2. Find the Hyper-V replica HTTP Listener (TCP-In) or Hyper-V replica HTTPS Listener (TCP-In), then right click it and select Enable Rules.

Note: Please do not forget to set up another host in the same way.

Step 3. Enable replica of virtual machine

1. Right-click on the VM, then click Enable replication to start the replication server setting.

2. Before You Begin: click Next.

3. Specify Replica Server: click Browse to select replication server, then click Next.

4. Specify Connection Parameters: check the configuration is right and click Compress the data that is transmitted over the network, then click Next.

5. Choose Replication VHD: select the VHDs you want to replicate in the box, and click Next.

6. Configure Replication Frequency: select the frequency of sending changes to the replica server (Hyper-V's default replication frequency is 5 minutes), then click Next.

7. Configure Additional Recovery Points: choose how many recovery points you want to keep in the replica server. If you choose Maintain only the latest recovery point, it is to store only the most recently received replicated data. If you choose Create additional hourly recover points, it keeps one or more points, which are created approximately every hour, and additional recovery points also require more space for storage.

8. Choose Initial Replication Method: In order to transfer the current state of the virtual machine to the replica server, specify the plan and schedule the replication task, then click Next.

9. Summary: check the settings, then click Finish.

Return to Hyper-V Manager to check the replication status, and when it is done, all changes will be sent to the replica host regularly.

Hyper-V Replica ≠ Backup

Replication can be used for fast disaster recovery, but it cannot replace backup in Hyper-V. Replica is not able to keep virtual machine files for a long time and requires more bandwidth. So, Hyper-V backup is more secure and efficient.

If you want to keep VM data for a long time and also perform fast recovery, you’d better choose a professional backup tool for VM management. Next, I will choose AOMEI Cyber Backup software to explain how to achieve secure backup and fast restoration.

For AOMEI Cyber Backup, it is a software that specializes in backup and data security. It provides you with centralized management, automatic backup and fast recovery. Meanwhile, it is able to store virtual machine to local system or network for a long time and saves bandwidth.

*You can choose to install this VM backup software on either Windows or Linux system. For business continuity and data protection, please follow the video to achieve these goals using AOMEI Cyber Backup.

1. Install AOMEI Cyber Backup, and add devices such as VMware ESXi Backup or Hyper-V Backup.

2. Target: select a destination to store the backup files such as  network or local place.

3. Schedule backup task: select full backup/ incremental backup as backup method for virtual machines, and set up time as daily/ weekly/ monthly to run the task automatically.

4. Select retention period: set up a retention period for each backup. Beyond the scheduled data, this software will delete the old files to save the storage.

After creating the backup tasks, it will continually protect your useful data.

5. Click Restore >> Restore to original / new location. Once the primary VM is damaged, it’s convenient and fast to restore the VM to another or original place, which ensures data security and keeps business continuity.

Summary

In this article, I have introduced how to set up Hyper-V Replica for fast disaster recovery, but there is one thing to note that it’s not wise to replace backup with replication or Hyper-V checkpoint. So, the best way for important data protection is backup.

For data security and business continuity, I recommend you to combine backup and replica for flexible use.