Skip to main content
Add as a preferred source on Google


Microsoft Enhances Hyper-V R2 for Failover Clustering

Microsoft announced earlier this month that failover cluster support using Hyper-V R2 has gotten a boost. Hyper-V R2 now supports a maximum of 1,000 virtual machines (VMs) in a cluster. Previously, in May, the hypervisor just supported a total of 960 VMs per cluster. A cluster can be defined as a grouping of host machines and their VMs that are managed as one entity. Typically, there would be at least two physical computers in a cluster, with one serving as the master (or job scheduler) and the other as the slave (performing the work).

The increased capacity was enabled because Hyper-V R2 now supports up to 384 VMs per node. Microsoft described the earlier limitations in a blog post on Wednesday.

"Until May 2010, the support limit was 64 VMs per host and up to 16 nodes in a cluster with one node for failover (a 15+1 cluster) for a total of 960 VMs," the blog explained.

Users of Hyper-V R2 -- either the standalone server or the one rolled into Windows Server 2008 R2 -- can vary the number of VMs per node for a maximum of 16 nodes per cluster. Microsoft supplies a table illustrating the possible number of VMs per node in its blog post.

Microsoft recommends reserving at least one node as a failover for the cluster. This failover node, or "passive node," stays idle, waiting to take over work should another node fail. With one node reserved for failover, a typical cluster may leverage a maximum of 15 nodes.

Microsoft further cautions that the number of VMs that can be run at the same time depends on three factors:

  • "Amount of physical memory being used by each virtual machine.
  • "Networking and storage bandwidth.
  • "Number of disk spindles, which affects disk I/O performance."

Microsoft describes the requirements for running VMs using Hyper-V, as well as the limitations, in a TechNet article here.

About the Author

Kurt Mackie is senior news producer for 1105 Media's Converge360 group.

Featured

  • large cloud icon with abstract code and interconnected polygons

    Report: Enterprise AI Workloads Are Tipping Toward Private Cloud

    Broadcom's 2026 Private Coud Outlook report says enterprise AI is moving from experimentation into production, with private cloud emerging as the preferred deployment environment for AI inference among surveyed organizations.

  • digital brain integrating legal regulation and security interface

    Survey: Agentic AI Moves from Pilot Phase to Production, Bringing Governance to the Forefront

    A new report from Caylent, an AI-focused Amazon Web Services Premier Tier Services Partner, found that enterprises are already moving agentic AI beyond pilots and into production environments. At the same time, organizations are putting strict conditions around autonomy, making governance and control the next major challenge for enterprise AI adoption.

  • Young Woman Programmer Uses Laptop To Analyze Neural Network Models

    AI Leaders Warn of Risks at United Nations Security Council Briefing

    The heads of OpenAI, Anthropic, and Hugging Face recently joined AI researcher Yoshua Bengio at the United Nations headquarters in New York to warn the UN Security Council about the security risks of increasingly capable AI.

  • abstract smartphone translucent screen displaying AI interface

    Apple Unveils Redesigned Siri AI

    At its recent Worldwide Developers Conference, Apple announced Siri AI, a redesigned version of its voice assistant that Apple describes in its own announcement as "a profoundly more capable and personal assistant." The update is intended to make Siri more conversational, more context-aware, and more useful across iPhone, iPad, Mac, Apple Watch, and Vision Pro.