Let’s say you’re operating a popular restaurant. In order to serve the clients efficiently, you require an orderly kitchen where the chefs (applications) have access to work without any hindrances. Now consider Kubernetes as the kitchen manager such that each chef receives the correct tools and ingredients (resources) at the appropriate time. However, the real question is this: Should your kitchen (Kubernetes) run in a common area with walls (VMs) or gain direct access to the whole kitchen (bare metal)?
Most businesses use Virtual Machines (VMs) because they provide flexibility, like dividing a large kitchen into separate cooking stations. However, this setup adds layers of complexity, just like chefs having to wait for shared equipment. Kubernetes on Bare Metal, on the other hand, removes those barriers giving applications full access to resources, improving speed, reducing delays (latency), and even cutting costs. Kubernetes is the leading container orchestration system with 92% market share according to the Cloud Native Computing Foundation (CNCF). Companies that deploy Kubernetes can either use VMs or bare metal servers. While VM-based Kubernetes is more flexible and abstracted, bare metal Kubernetes performs better with greater performance, less latency, and cost savings.
In this step-by-step tutorial, we will talk about Kubernetes on bare metal, its pros and cons, step-by-step installation, best practices, and key considerations.
Understanding Bare Metal Kubernetes
What Is Bare Metal Kubernetes?
Bare metal Kubernetes is the deployment of Kubernetes clusters on physical servers directly without an intermediary virtualization layer. Unlike traditional Kubernetes installations from VMs, bare metal Kubernetes provides direct access to hardware with maximum resource utilization.
How Bare Metal Kubernetes Works?
When Kubernetes runs on VMs, a hypervisor runs one or more virtual machines that each run a unique Kubernetes node. Such VMs consume additional CPU, memory, and networking resources due to virtualization overhead.
Bare metal Kubernetes, in contrast, deploys directly onto the host machine with no hypervisor layer. The direct hardware integration leads to:
- Improved performance: Containers run with minimal overhead.
- Reduced latency: No hypervisor = less communication latency.
- Efficient use of resources: Applications have immediate access to hardware resources.
Main Features of Kubernetes on Bare Metal
1. Direct Hardware Access
Applications running in Kubernetes clusters gain direct access to hardware resources without going through a hypervisor, which translates into the optimum possible performance for CPU-bound or memory-intensive workloads.
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2. No Virtualization Overhead
No virtual machines exist, and therefore there is no additional use of resources by hypervisors or VM management layers.
3. More Hardware Configuration Control
Organizations can tailor hardware configurations based on workload requirements without being limited by VM constraints.
4. Enhanced Networking
Bare metal Kubernetes supports high-speed and native networking without the additional network translation that is present in VM-based scenarios.
Use Cases of Kubernetes on Bare Metal
1. Performance-Critical Workloads
Gaming, finance, and AI analytics workloads require high-performance computing with low overhead. Bare metal Kubernetes provides the performance and efficiency needed for these types of workloads.
2. Latency-Sensitive Workloads
Telecom, real-time analytics, and gaming platforms benefit from bare metal Kubernetes due to reduced network latency.
3. GPU-Accelerated Workloads
AI, machine learning, and data science workloads frequently require direct access to GPUs. Bare metal Kubernetes enables maximum GPU usage without virtualization limitations.
4. On-Premise Deployments
Existing physical infrastructures of the organizations can capitalize on Kubernetes deployment on bare metal to remain budget-friendly without expenses on cloud services.
Kubernetes on Bare Metal vs. Kubernetes on VMs
| Factor | Kubernetes on Bare Metal | Kubernetes on VMs |
|---|---|---|
| Performance & Latency | Higher performance, lower latency (direct hardware access) | Slightly lower performance due to hypervisor overhead |
| Resource Utilization | Full access to physical hardware | Limited by VM constraints |
| Setup & Scalability | More complex setup, harder to scale dynamically | Easier setup with VM orchestration, better scalability |
| Failure Recovery & Networking | Requires manual failover and networking setup | VMs offer better failover mechanisms and simplified networking |
| Cost & Security | No hypervisor costs, better security with direct OS control | Additional VM software costs, shared hypervisor risks |
Advantages of Kubernetes on Bare Metal
1. Improved Performance – Applications execute faster, more efficiently, and responsively since they do not experience hypervisor overhead.
2. Improved Latency – Since bare metal deployment offers faster data processing and network communication, they are suited best for latency-sensitive applications.
3. Cost Effectiveness – Organizations who already own physical servers do not have to pay for cloud migration and the expense of hypervisor licenses and VM administration.
4. Security and Compliance – Hardware direct access enables organizations to put in place strong security controls, and thus bare metal Kubernetes is ideal for industries with strong compliance needs.
5. Resource Maximization – Unlike VMs, where each virtualized instance has a share of resources, bare metal Kubernetes enables applications to utilize 100% of CPU, memory, and storage.
Disadvantages of Kubernetes on Bare Metal
1. Complicated Setup and Configuration – Installation of Kubernetes on bare metal entails configuring each individual physical node manually, thus the process is more complicated than in the use of VMs or cloud services.
2. Dangers of Node Failure – As opposed to VM-based systems, where a crashed node can be merely reinstalled, a bare metal server crash will result in downtime unless there is a high-availability routine in place.
3. Difficulties in Backup and Migration – Without virtualization, backups or workload migration between servers are done with special tools and techniques.
4. Difficulty in Operations – Kubernetes bare metal management requires hardware, network, and Kubernetes internals expertise, and therefore is slightly more difficult to manage than cloud Kubernetes.
Step-by-Step Guide to Deploying Kubernetes on Bare Metal
Pre-Requisites
To prepare for Kubernetes on bare metal installation, ensure that you have:
- Minimum two physical servers running Linux (Ubuntu 20.04 and above).
- Root or sudo access to both servers.
- Access to the internet to download necessary packages.
- SSH access to control remote nodes.
Step 1: Install Essential Packages
On each server, update the system and install Docker:
sudo apt update
sudo apt install -y docker.ioEnable and start Docker:
sudo systemctl enable docker
sudo systemctl start dockerStep 2: Install Kubernetes Components
Add the Kubernetes repository and install kubelet, kubeadm, and kubectl:
sudo apt update && sudo apt install -y apt-transport-https
curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add -
echo "deb http://apt.kubernetes.io/ kubernetes-xenial main" | sudo tee -a /etc/apt/sources.list.d/kubernetes.list
sudo apt update && sudo apt install -y kubelet kubeadm kubectlDisable swap memory on every node:
sudo swapoff -aStep 3: Initialize the Kubernetes Cluster
On the master node, run the following command to initialize the cluster:
sudo kubeadm init --pod-network-cidr=10.244.0.0/16Copy the `kubeadm join` command from the output and use it to join worker nodes.
Step 4: Configure kubectl for Cluster Management
On the master node, execute:
mkdir -p $HOME/.kube<br>sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config<br>sudo chown $(id -u):$(id -g) $HOME/.kube/configStep 5: Add Worker Nodes
On every worker node, use the copied `kubeadm join` command to add them to the cluster.
Step 6: Deploy a Network Plugin
Choose a pod network (Flannel, Calico, or Cilium) and apply it:
kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.ymlVerify that all nodes are active: kubectl get nodes<br>Best Practices for Bare Metal Kubernetes
- Use high-performance CPUs, SSDs, and ample RAM for peak cluster performance.
- Employ multiple master nodes and network redundancy to reduce downtime.
- Employ infrastructure-as-code solutions such as Terraform or Ansible to handle server configurations.
- Install monitoring solutions such as Prometheus and Grafana to monitor system health.
- Update Kubernetes and its dependencies to avoid security loopholes.
Conclusion
Kubernetes on bare metal offers unparalleled performance, efficiency, and cost savings to organizations that require high-speed processing and direct hardware access. But this comes at the expense of increased setup complexity and operational difficulties. With optimal practices and a streamlined deployment process, organizations can harness the potential of bare metal Kubernetes for peak performance and reliability.
FAQs
What is bare metal Kubernetes?
Bare metal Kubernetes is the installation of Kubernetes on physical servers without having a virtualization layer. This is more efficient in terms of performance, latency, and usage of all resources because it does away with the VM overhead.
Can I run Kubernetes on old hardware?
Yes, but performance will suffer. Kubernetes is a benefit in systems with new CPUs, SSDs, and high-speed network devices. In older systems, optimize low overhead configurations to prevent resource bottlenecks.
Is Kubernetes on bare metal suitable for small businesses?
Yes, if only they have in-house expertise to handle it. For small companies that do not have a specific DevOps team, managed Kubernetes service or VM-based environment could be a better option.
Is it worth running Kubernetes on bare metal?
If you require high performance, low latency, hardware control, and low cost, then absolutely. However, it is a tremendous amount of operation work that has to be undertaken, and organizations have to consider the advantages against the complexity of having to provision their own infrastructure.
