Building a Hyper-V failover plan is a critical step for any organization wishing to maintain 24/7/365 availability of their Microsoft Cloud. However, configuring Hyper-V failover clusters and managing Hyper-V hosts has its own set of unique challenges and nuances. This article provides an introduction to Hyper-V failover challenges, discusses its benefits and shares some resources where virtualization administrators can access more information.
A Brief Introduction to the History of Hyper-V Failover Clusters
A Hyper-V failover cluster is a group of Hyper-V hosts that can synchronize in a way so that one host can take the load (virtual machines, services, processes, etc) if another fails or suffers performance issues. Windows Server Administrators who wish to fortify their server workloads have a helpful option – Hyper-V failover clustering – right inside Windows Server 2012 R2, Windows Server 2012, Windows Server 2016, and 5nine Cloud Manager.
Shared VHDX format was introduced in Windows Server 2012
Microsoft introduced the concept of Shared VHDX with Windows Server 2012. This feature enabled Windows admins to attach a Virtual Disk (VHDX) to multiple virtual machines to create guest clusters. Although Windows Server 2012 R2 improved upon the existing Hyper-V failover process, it still lacked key features in the areas of host-based backup and online resizing of shared VHDX files. Windows Server 2016 filled those availability gaps by providing missing VHDX capabilities, Virtual Machine Resiliency, Storage Replica and more.
How Hyper-V Failover Clustering Works
Failover clustering includes systems that continually monitor clustered machines and operations to verify performance and uptime. If problems are found, workloads are moved from one node to another, so they can resume normal operations shortly after migration. Additionally, the inclusion of Cluster Shared Volume (CSV) functionality makes Hyper-V clustering even more versatile. The feature provides a consistent, distributed namespace that clustered roles can use to access shared storage from all nodes, with minimal disruptions.
Example of Hyper-V Failover Cluster Architecture
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Hyper-V Failover Cluster Hardware Requirements
Hardware requirements for failover clusters include storage that is attached to the nodes in the cluster, as well as the use of device controllers or adapters such as Serial Attached SCSI (SAS), Fibre Channel, Fibre Channel over Ethernet (FcoE) or iSCSI. In addition, the complete cluster configuration (servers, network and storage) must pass all tests in the Validate a Configuration Wizard.
According to the April 2017 Microsoft guide to deploying Hyper-V clusters, failover clusters can be configured with up to a maximum of 64 nodes, with up to 1,024 virtual machines on a single node, provided that the server hardware has the resources to support them. A maximum of 8,000 virtual machines can be arranged on each cluster – enough to cover the needs of most modern software-defined datacenter customers.
Hyper-V Failover Cluster Management Options
Failover clusters can be managed by using the Failover Cluster Manager snap-in, Windows PowerShell or by using 5nine Cloud Manager (the easiest and fastest of the three). Each of these tools has its own benefits, but only 5nine Cloud Manager provides a comprehensive, slick GUI for centrally managing Hyper-V.
Hyper-V failover cluster management is only available through the Failover Cluster Manager
The Failover Cluster Manager enables Windows administrators to create, configure, manage, test and migrate virtual machines. Although functional, the Failover Cluster Manager snap-in is complex and is reported to crash, after service updates and during general use.
Failover Cluster Management with PowerShell is effective but requires deep scripting know-how
PowerShell is a powerful scripting tool for managing and automating Hyper-V failover cluster functions. It also requires deep knowledge of PowerShell commandlets and functionality. To use PowerShell for Hyper-V Cluster Management, a Windows Server Admin would first need to install the failover clustering feature on each server that includes the cluster (of which they’ll need administrative privileges), and second, go through the process of configuring PowerShell Cluster CMDlets.
5nine Cloud Manager, the easiest and most comprehensive of the three options enables you to centrally create, validate, monitor and manage Hyper-V Failover Clusters
Quickly Create and Validate Hyper-V Clusters
5nine Cloud Manager allows you automatically discover host servers and define which ones make up the failover cluster. An intuitive, step-by-step wizard takes you through the process of specifying nodes, validating clusters and assigning access points.
Validating Hyper-V failover clusters is a critical, and required step for Microsoft Cloud availability. 5nine empowers you to test the health of your Hyper-V failover cluster before, during and after deployment. By monitoring Hyper-V failover cluster health during each stage of the configuration, you’ll be able to more easily identify issues.
Automatically Analyze and Optimize Hyper-V Host Performance
5nine Cloud Manager includes a Best Practices Analyzer table that enables you to automatically test Hyper-V on each host and Scale-Out File Servers running in your environment. The streamlined GUI will proactively recommend performance enhancements in addition to providing error and warning statuses.
Configure Hyper-V Cluster Live Migration in Just a Few Steps
Live Migration ensures that VM traffic doesn’t interfere with critical services. 5nine Cloud Manager providers the granular ability to specify the number of simultaneous Live Migrations and Storage Live Migrations that can occur at any one time. The granularity and visibility of the Live Migration process in 5nine Cloud Manager will help you accelerate and more easily manage your failover operations.
Monitor Hyper-V Failover Cluster Health and Performance
5nine Cloud Manager includes dashboards that visually display the health status of individual nodes and VMs within the environment. Its unified GUI pulls in KPIs from disparate nodes so you can see every detail from a single access point. The centralized view eliminates the manual effort and saves time associated with moving from host to host to diagnose and troubleshoot Hyper-V performance.
It also includes a centralized dashboard to monitor current and historical Hyper-V usage data for clusters, hosts and VMs. It quickly shows which VMs are consuming the majority of resources, provides an overview of the most recent alerts and graphically displays CPU, memory, disk and network usage. You can even browse previous performance data to help isolate persistent problems.
Manage Hyper-V Cluster Nodes and Hyper-V Clustered VMs
5nine Cloud Manager provides central management and configuration of the virtual disk and network settings across the Hyper-V environment. Hyper-V Cluster Management functions include operations like pause, resume and migrate.
5nine also supports management for virtual machines with any guest operating system. This includes Windows Server, Windows, Linux and UNIX. By managing heterogeneous Hyper-V Clusters with 5nine Manager, you’ll save time and reduce potential errors. Plus, 5nine solutions are continually updated to support the latest performance and security features so that you don’t have to. The GUI runs on any version of Windows server, including GUI-less versions like Windows Server Core.
A full list of Hyper-V Cluster operations can be found in the interface or on the 5nine Knowledge Base.
5nine Cloud Manager: A Simple Alternative to Failover Cluster Manager on Hyper-V Server
Hyper-V failover clusters are worth investigating for your company's IT systems because of the clear and significant benefits they can provide for your workload uptime and reliability, as well as for their performance benefits.
5nine Cloud Manager provides a unified graphical interface for configuring, monitoring and managing Hyper-V VMs across hosts. Rather than having to open multiple Failover Cluster Manager consoles, it unifies everything into a single screen. The solution simplifies configuration, management and maintenance of Hyper-V clusters so administrators have more time to focus on other tasks. 5nine offers a free 14-day evaluation of its Cloud Manager and provides a free community version for up to 3 hosts.
Hyper-V failover clusters provide high availability and robustness for your environment by reducing many – but not all – points of failure. They can also increase your system configuration and deployment options, as server applications can be run on physical servers or on virtual machines.
While not a perfect fit for every situation, failover clusters offer significant benefits for Hyper-V and other server applications; including Microsoft Exchange Server, Microsoft SQL Server, and file servers. If you are interested in building a Hyper-V failover plan for your business, 5nine is here to help you with the expertise and answers you need to get your Hyper-V environment configured, managed and deployed to meet your needs.
Editor’s Note: This post was originally published in March 2018 and has been completely revamped and updated for accuracy and comprehensiveness.
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.