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VMware vSphere delivers greater out-of-the-box VM density than Red Hat Virtualization

vSphere supported 160% as many VMs with out-of-the-box settings.

A third-party study shows that VMware® vSphere® 6.5 supports more virtual machines with out-of-the-box settings than Red Hat Virtualization 4.1.

Higher density, lower CapEx

The higher the VM density, the lower the per VM capital costs. This is a key advantage VMware vSphere provides to customers. Using advanced memory management VMware vSphere easily assigned more virtual memory to VMs than the total physical memory available. Red Hat Virtualization had trouble with this routine operation.   

The study also showed that operators can rely on vSphere memory management to keep critical applications running even when hardware fails unexpectedly. Red Hat KVM struggled to keep VMs powered on and running. VMware vSphere worked without hesitation and without any admin tuning.  

How we tested

Principled Technologies (PT), an independent testing facility, used hands-on testing to investigate virtual machine density. PT compared VMware vSphere 6.5 and Red Hat Virtualization (RHV) 4.1 running Microsoft® SQL Server® 2016 VMs on a Lenovo™ System x3650 M5 rack server. PT first determined how many VMs each hypervisor could power on and run an online transaction processing workload. Then they increased the number of VMs to test the range each virtualization platform could support. PT used default hypervisor memory management settings.  Using these out-of-the-box settings, vSphere was able to power on and run 160% more VMs than it—or RHV—could run without memory over commitment.  

Additional testing showed that during a simulated hardware failure vSphere also kept VMs available without administrator intervention. RHV required an admin to enable Memory Optimization and perform manual tuning to overcommit memory. Even then, RHV could power on and run only 107 times its baseline number of VMs and could not deliver high availability.  

This study offers further confirmation that VMware vSphere continues to be the most reliable, trusted and cost-effective virtualization technology on the market. You can read the entire report here.

2 thoughts on “VMware vSphere delivers greater out-of-the-box VM density than Red Hat Virtualization

  1. Giovanni Vecchi

    “RHV required an admin to enable Memory Optimization and perform manual tuning to overcommit memory.”
    Transparent Page Sharing is no longer enabled by default even in ESXi…

    1. Eric Horschman

      Giovanni – You’re correct about ESXi Transparent Page Sharing, but that point was acknowledged in the Principled Technologies report:
      “Note that admins can also enable Transparent Page Sharing to consolidate memory even further; because we wanted to represent the out-of-the-box experience with vSphere, we did not enable Transparent Page Sharing or use it in any of our tests.”

      What allows ESXi to deliver better VM density in a default installation is its multiple levels of memory management technology that are always on and working to conserver memory: memory compression, guest memory ballooning, and highly efficient host swapping that can be accelerated with flash storage.

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