A subsequent study comparing the two environments showed that vSphere with Tanzu also required up to 28% less storage and up to 22% less memory compared to Red Hat OpenShift on bare metal. Scroll below for more details.
What was tested
Principled Technologies (PT), an independent lab facility, tested VMware vSphere 7 U2 with Tanzu and bare metal Red Hat OpenShift 4.7 to investigate container pod density 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 Kubernetes workloads. The OpenShift deployment also needed three additional hosts to be configured as management nodes.
PT used a stateless webservice workload to scale the number of pods. Each pod in the workload ran a replica of a website, and a standard Kubernetes load balancer split the traffic evenly across all pods.
What Principled Technologies found
PT found that 13,700 pods were supported by vSphere with Tanzu versus only 2,150 pods supported by a Red Hat OpenShift bare metal deployment on identical hardware.
On the Red Hat OpenShift deployment, PT stopped scaling up the pods when they started seeing worker node instability, at 2,150 pods. Red Hat documents a default of 250 pods but allows this to grow to a maximum of 500 via additional configuration. For this testing, PT increased the OpenShift pod limit to 500 using the configuration knobs.
On the vSphere with Tanzu platform, PT stopped scaling up the pods at 13,700 pods, when the memory utilization reached 95% to avoid performance deterioration. vSphere with Tanzu was not only able to reach 6.3 times the number of pods, but also did not suffer node instability issues.
This study confirms that VMware provides an efficient and cost-effective platform for modern applications. For further details and the science behind the testing, check out this report by Principled Technologies.
Higher container pod density results in lower Capex
The higher pod density translates to lower cost as the number of physical hosts required to run the same number of containers will be lower. By abstracting physical hardware, vSphere with Tanzu allows for better utilization of resources than OpenShift on bare metal. This is a key advantage that virtualization offers over bare metal.
vSphere with Tanzu offers efficiencies in storage and memory usage
PT conducted additional testing on the VMware vSphere 7 U2 with Tanzu and bare metal Red Hat OpenShift 4.8 environments to compare storage and memory efficiency by executing a series of Kubernetes resource management scenarios on identical hardware as before. They used Redis, a NoSQL database to provide a large dataset to emulate a real-world scenario.
For the storage comparison, vSphere with Tanzu using vSAN was tested with storage policy options of RAID 1 (default policy of mirroring) and RAID 5 (parity). Red Hat OpenShift using OpenShift Data Foundation offers three-replica (default policy with three copies) and two-replica (mirroring) storage policy options, but no parity option. The vSphere with Tanzu cluster used 28.2% less storage for its default mode of RAID 1 when compared to Red Hat OpenShift cluster with default mode of three replicas. For the space savings mode of RAID 5, vSphere with Tanzu cluster saved 17.5% storage space when compared to the space saving option of two replicas on the Red Hat OpenShift cluster.
For the memory comparison, vSphere with Tanzu offers better efficiency due to vSphere Transparent Page Sharing (TPS) capability. TPS securely eliminates redundant copies of memory pages within a worker node VM, thereby saving space. OpenShift on bare metal does not have this capability. Due to this, vSphere with Tanzu used 22.1% less memory when compared to the OpenShift on bare metal cluster. For further details and the science behind the testing, check out this report by Principled Technologies.
Virtualization brings operational savings to containerized workloads
vSphere with Tanzu transforms familiar enterprise VM infrastructure into a developer-ready container platform where Kubernetes runs natively on the hypervisor. Well-known vCenter tools and processes can now manage both traditional VM-based and containerized workloads across your hybrid cloud. vSphere brings trusted capabilities such as high availability and policy-based management to ensure availability and resiliency for all workloads. vSphere also enhances security of containers by naturally providing isolation of pods inside the VMs. Finally, vSphere life-cycle management and enterprise resiliency reduces admin time required to manage bare metal updates and failures.
To learn more about these benefits in detail, check out Why Choose VMware Virtualization for Kubernetes and Containers.
Principled Technologies: Kubernetes on VMware vSphere vs. bare metal: Which delivered better density and performance?