Kubernetes on bare metal: what you need to know

Cloud-based Kubernetes services are popular and save time by allowing clusters to be set up with just a few clicks. However, some companies are choosing to run Kubernetes on bare metal. Recent research from Spectro Cloud shows that 20% of enterprise users choose K8S on bare metal, which is expected to keep growing.

Kubernetes doesn’t care whether it runs on physical servers or virtual machines. But in many cases, using physical servers without the extra layer of virtualization offers significant benefits:

Maximum performance: Running K8S on bare metal means both Kubernetes and your applications directly use the physical server’s resources like GPU, CPU, memory, and network cards. Such setup provides the best performance and lowest latency, which is crucial for tasks like managing large databases, machine learning, AI training, and more.

Infrastructure flexibility: K8S on the bare metal gives you full control over all system settings. You can take advantage of unique hardware features, like specific GPU/CPU instructions or special network card functions, and access all server and OS configurations. In many cases, cloud infrastructure or virtual machines don’t offer the specific settings you might need, but bare metal allows you to tailor everything to your requirements.

Complete security control: Even though cloud solutions are secure, they might not meet your project’s specific needs. If you require a particular security setup that your cloud provider can’t offer, K8S on bare metal gives you the freedom to implement it yourself. Plus, by avoiding virtualization, you reduce the risk of attacks targeted on hypervisors and virtual machines.

Cost control: Kubernetes on bare metal can help you use resources more efficiently and reduce costs for always-on clusters. While cloud providers charge for active resources, the cost can quickly exceed the cost of maintaining a physical server platform as your infrastructure grows. If you already have skilled personnel, the cost and benefits of K8S on bare metal become clear.

However, running Kubernetes on bare metal also brings some challenges for the support team.

Node configuration: Instead of setting up virtual machines, you’ll need to configure actual hardware. It might involve dealing with hardware compatibility issues, kernel modules, and drivers to optimize Kubernetes. You’ll also be responsible for setting up the network, DNS, and storage configurations. Scaling the cluster requires manual preparation of nodes and adding them to your cluster. You can use proper tools but they aren’t as easy to use as managed services or virtual machine-based setups.

Backup and migration: Without virtual machine snapshots, you’ll need a different approach to backup and migration. Also, find new ways to back up server OSes and move them to other hardware.

Scaling planning: Scalability is important for Kubernetes on bare metal. Predicting future growth, you need to design your infrastructure with additional nodes, storage, and network equipment in mind.

Ensuring high availability: Bare metal setups require setting up load balancers, backup network switches, power sources, and other backup equipment. You’ll also need to configure the etcd database, control plane nodes, and worker nodes to ensure they can handle failures.

Security measures: Kubernetes on bare metal requires security measures at both the physical and software levels. It’s important to plan and implement strong security practices like strict authentication, secret management, and network traffic encryption as early as possible.

Monitoring сonfiguration: You’ll need to create and implement your monitoring system using tools like Prometheus, Grafana, and Loki. Setting up log processing and alert notifications for important infrastructure events is also crucial.

Conclusion: Although the number of companies using Kubernetes on bare metal is still small, it’s growing. This approach benefits large companies with extensive container infrastructures and smaller projects with high-performance needs. The main reason for choosing Kubernetes on bare metal is its superior performance in 90% of cases.

Serverbee has experience deploying K8S on bare metal and supports those considering this option. If you’re interested, feel free to contact us — we’d be happy to discuss collaboration or answer any questions you may have.