VM performance vs physical servers – practical experience

Dan Zeng

In production, I’ve been running both VMs and physical servers. Virtualization clearly brings huge flexibility:

Snapshots for quick rollbacks

Easier migration and resource scheduling

Better overall hardware utilization

But when it comes to performance, the difference is still noticeable in some cases. Especially for I/O-intensive workloads like databases, VMs tend to show higher latency and lower throughput compared to bare metal.

With modern hypervisors and optimized hardware, the gap has narrowed a lot, but from my experience:

General workloads and mid-level applications run perfectly fine on VMs

Mission-critical, performance-sensitive apps (databases, big data) are safer on physical servers

VM performance can be improved by properly allocating vCPU/memory, optimizing storage I/O paths, and avoiding long snapshot chains

This layered deployment approach helps balance virtualization flexibility with the stability required by critical workloads.

Alistair

👍 Totally agree. We also keep critical DBs on bare metal, and push the rest to VMs. Once we tuned storage I/O and limited snapshot chains, performance improved a lot — virtualization works great when used wisely.

Sylas Beaumont

Containers can be a useful middle ground — much lighter than full VMs and often closer to bare-metal performance when paired with local NVMe.

Quentin

Have you measured latency for those DBs on both metal and VMs? Real benchmark numbers make this decision concrete.

Desmond Caldwell

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