vSphere Supports Better VM Density Compared to OpenShift Virtualization

A new third-party study from Principled Technologies shows that vSphere supports double the number of active SQL Server VMs, requires less admin hands-on time and provides more functionality than the OpenShift Virtualization solution.

In addition to VMs, vSphere with Tanzu empowers admins to manage containerized workloads on the same platform. While OpenShift claims to bring VMs into containerized workflows with OpenShift Virtualization, the VM operations are done using Kubernetes commands generally in a command line interface.

What was tested

Principled Technologies (PT), an independent lab facility, compared two virtualization solutions: VMware vSphere 7 U2 and OpenShift Virtualization on the Red Hat OpenShift 4.9 platform. The testing was done using an identical five-host cluster with HPE ProLiant DL380 Gen 10 servers. For both vSphere and OpenShift, the five hosts were configured to run the VM workloads. Note that the OpenShift deployment also needed three additional identical hosts to be configured as management nodes.

On this identical hardware, PT performed testing to investigate the number of active and idle VMs each solution supported, as well as the amount of time and effort needed to perform routine admin tasks.

What Principled Technologies found

The testing found that vSphere is a more intuitive, enterprise-ready solution for running VM workloads compared to OpenShift Virtualization on the Red Hat OpenShift platform:

  • vSphere provides better resource management (more VM density = less Cap Ex)
    vSphere supported 2 times as many active SQL Server VMs and 4 times as many idle VMs. In addition, because vSphere automatically balances the load across servers during operation, fewer admin interaction is needed to ensure that balanced load on nodes.

  • vSphere automatically restarts failed VMs on alternate hosts in the cluster
    Failures are inevitable and vSphere allows for high availability by simply checking a box, whereas OpenShift Virtualization requires a yaml script to fulfill the same functionality. vSphere HA restarts the failed VMs on alternate hosts in the event of a failure, whereas OpenShift Virtualization forcibly reboots a virtualization host if it is unresponsive for a specific amount of time leading to downtime. Finally, vSphere takes almost 5 minutes less to bring a VM back online after a failure.
  • Performing routine update tasks are seamless on vSphere
    Host and cluster maintenance are routine tasks performed by an admin to keep everything up to date. vSphere has live migration capabilities to make sure there are as few service interruptions as possible. vSphere required less time to migrate an active VM from one host to another. It also allows for an active VM to be moved from one storage pool to another without any downtime, whereas OpenShift Virtualization needed the VMs to be offline. vSphere also has multiple other live migration options for a true enterprise experience, such as support for live migration between heterogeneous nodes and encryption of VM live migrations.
  • Upgrading hardware does not need downtime on vSphere
    Sometimes it becomes necessary to scale up a VM’s compute resources because your workload requirements increase. vSphere supports “hot-add” capability for CPU and RAM with no downtime. On the OpenShift environment, the admin must take a VM down each time they want to increase the compute or memory capacity.


Virtualization solutions have been around for a long time and have evolved to provide enterprise-grade features that many customers rely on and expect. VMware vSphere has pioneered many of these capabilities. Today, as enterprises are modernizing their applications, vSphere with Tanzu allows you to run Kubernetes workloads on the same virtual infrastructure with unified management for containers and VMs.

While RedHat OpenShift platform claims to support VMs through OpenShift Virtualization, it is important to note the key distinctions in capabilities versus vSphere as is evident from this Principled Technologies study.

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vSphere with Tanzu supports 6.3 times more container pods than bare metal OpenShift