Summary
Bare metal describes a physical server that runs workloads directly on hardware without an intervening hypervisor, offering maximum performance and predictable latency.
What is Bare Metal?
In cloud and data centre contexts, bare metal means dedicated physical hardware allocated to a single tenant or workload. There is no virtualisation overhead: the operating system interacts directly with the CPU, memory, storage, and network interfaces.
Bare metal is chosen when performance is critical—high-frequency trading, GPU compute, or latency-sensitive databases—because there is no hypervisor tax or noisy-neighbour effect. It is also preferred for workloads with strict compliance requirements that prohibit shared physical hardware.
Cloud providers offer bare metal as a service, where physical servers are provisioned on demand alongside virtual machines. Tools like Ironic (part of OpenStack) automate the lifecycle management of bare metal nodes in the same way Nova manages virtual machines.
Why is Bare Metal relevant?
- Performance: Direct hardware access eliminates virtualisation overhead for compute-intensive workloads
- Predictability: No contention with other virtual machines on the same host
- Compliance: Some regulations require dedicated physical hardware isolation
- Flexibility: Can run any hypervisor or container runtime on top