Hyper V replication is a process of continuous virtual machine data synchronization between two sites to ensure business continuity in case of an outage. There are two categories for a target replication site: a public or a private cloud. From a public cloud perspective, you can replicate to Azure using Azure Site Recovery.
Conversely, you can replicate to a Hyper V private cloud by using an onsite or remote location. Each category has advantages that pertain to individual use cases. Azure-based replications are ideal for organizations with a single datacenter. Hyper V replications work best for organizations with multiple datacenters that operate across various regions. They are especially useful in organizations that employ sensitive data like financial institutions or healthcare facilities.
Advantages of Hyper V to Azure Replication
The advantages of using Azure for a Hyper V replication include speed, convenience, cost efficiency and global reach. Getting started with Hyper V to Azure replication is as easy as subscribing for Azure Site Recovery, which can help you safeguard critical services by automatically replicating and recovering your Hyper V instances. Given Azure Site Recovery’s consumption-based pricing model, and its global reach, the public cloud is an ideal replication site. Overall, this system is perfect for organizations that don’t have a secondary datacenter and prefer a pay-as-you-go model.
Why Use Hyper V Replication
Many use cases demonstrate the value of Hyper V replication, but here are two typical examples I often hear about from customers. First, suppose that your primary site requires electrical work and the contractors need to cut the power temporarily. To ensure business, you could fail over virtual data to your remote replica site while your primary site is undergoing maintenance. Once the electrical work is done, you could fail back from your secondary site to your primary location, and business would continue as usual without disruption.
Second, consider an example where an environmental disaster like a fire, flood or hurricane threatens your primary site. Here, you could replicate at-risk machines to another site, so you could ensure business continues in a worst-case scenario. Downtime can cost an organization millions of dollars. According to Gartner, the cost of downtime is $5,600 per minute with a possibility to extrapolate well over $300,000 per hour. Given this cost, it’s imperative you adopt a business continuity plan.
Hyper V Replication Vs. Backup: What’s The Difference?
Many administrators make the mistake of considering replication to be the same as disaster recovery, but it’s not. The critical distinction between the two concepts is that backups are used in the event of a disaster while replication is more suitable for business continuity. For example, if you experience data corruption and lose both of your sites, you must perform a complete restore. In this case, the process can take hours if not days due to all the data that needs to be transferred from the backups to the disks. Conversely, replications aren’t as labor intensive and may take only a few minutes to complete. Therefore, replication is better suited for ensuring business continuity than traditional disaster recovery.
How to Plan Hyper V Failover
There are three types of Hyper V failovers in a business continuity model: planned, unplanned and automated. A planned Hyper V failover is a proactive process of switching off Hyper V virtual machines in your primary site and failing them over to a secondary site on a predefined schedule. An unplanned failover is a reactive process by which you fail over Hyper V VMs after a problem has already occurred. “Clustering” is a type of automated failover that allows you to move VMs to a target host if a Hyper V source host goes down.
Here is how you can plan for a replication project:
- Check the health of all your current replication jobs before the planned outage, so you can quickly resolve any issues.
- Turn off all the virtual machines to ensure data replicates correctly.
- Once all the virtual machines are shut down, you can failover to the remote site.
If you do not monitor the health of your jobs, you will encounter various Hyper V replication problems that will result in a failure or a bad replica. To avoid these problems, first, ensure you have the adequate bandwidth between your primary and replication sites. We advise scheduling replication jobs after normal business hours to ensure that it doesn’t deplete your bandwidth.
Next, ensure your secondary site has enough storage space for the replication data. A Hyper V host at storage capacity will fail before the replication is completed.
Always keep an eye on the overall cluster resource utilization. By leveraging some of the advanced capabilities of 5nine Cloud Manager, you can have clusters monitor themselves and get automated status updates no matter where you are.
See for yourself how 5nine Cloud Manager solves business continuity and disaster recovery challenges in Hyper V and Azure with a free 14-Day trial.
I am an author, speaker and technical evangelist focussed on Microsoft Cloud management and security. I’ve held product management and product marketing roles at early stage startups and enterprise software vendors, all with an emphasis on Microsoft technologies. As the Senior Evangelist for 5nine, I get to share the 5nine story with audiences all over the world. I talk, I blog, I record videos, and I spread the word via social media.