Why you wouldn’t run hundreds of containers directly on bare metal

Why you wouldn’t run hundreds of containers directly on bare metal:

  • Single point of failure → if the kernel or hardware dies, everything dies.

  • Kernel risk → one bad kernel update could wipe out hundreds of containers at once.

  • Hard to isolate performance issues → containers can still compete for CPU/memory in messy ways.

  • Hard to scale → bare metal doesn’t autoscale like cloud resources do.

Instead, the smart way is:

  • Use virtualization (VMs) or cloud-managed instances (like AWS EC2, Google Compute Engine, etc.).

  • Run maybe 20–50 containers per VM (depends, of course).

  • If a VM has a problem → only a small chunk of containers die, not everything.

  • Plus, cloud infra can autoscale, replace bad VMs, load-balance, etc.

Real-world setup:

  • VMs are the „crumple zones“ protecting your container workloads.

  • Kernel upgrades, patches, crashes → only affect one small batch at a time.

  • Easier to roll out changes, easier to recover.

Some people even go a step further:
Use Kubernetes (EKS, GKE, etc.) to spread containers across hundreds of small VMs → maximum flexibility + failure resistance.

If you find a company running Docker hosts on bare metal or VMware with hundreds or thousands of containers on each machine:

  • Every kernel update is a potential mass-extinction event.

  • Every hardware issue (disk, CPU, RAM) can kill hundreds or thousands of services at once.

  • Scaling is painful and manual.

  • Disaster recovery is slow and risky.

  • Monitoring and troubleshooting become nightmares — one crash = massive chaos.

  • Security risks are higher because everything is jammed together and hard to isolate cleanly.

  • You will be constantly firefighting instead of building things.

  • You will have endless maintenance windows, downtime, stress, and pager alerts.

✅ Conclusion:
If you find this setup → RUN. 🏃💨
Your life as an engineer will be miserable there.
Good companies spread the risk, automate scaling, design for resilience — they don’t stack containers like Jenga towers. 🧱

Docker / Container Red Flags:

  • ❌ „We run hundreds or thousands of containers per Docker host.„
    → Means they stack containers dangerously, single point of failure.

  • ❌ „Our Docker hosts are on bare metal.„
    → Means no hardware fault tolerance.

  • ❌ „We use VMware for Docker hosts.„
    → Means they think virtualization magically solves container issues (it doesn’t).

  • ❌ „Kernel updates are rare / manual / scary.„
    → Means containers are tightly tied to an unstable foundation.

  • ❌ „Scaling? We just add bigger servers.„
    → Vertical scaling = disaster scaling.

  • ❌ „Our disaster recovery is… well, backups.„
    → No fast recovery plan = you’re screwed during an outage.

  • ❌ „We don’t use Kubernetes, ECS, EKS, or anything like that.„
    → Means they manually herd containers, like cavemen with sticks.

  • ❌ „Containers sometimes crash, and we just reboot the host.„
    → Huge operational pain, no proper health checks or orchestration.

✅ Green Flags you want to hear:

  • „We spread containers over many small instances.“

  • „We use managed services (EKS, GKE, ECS).“

  • „We have automated health checks, rolling updates, blue/green deployments.“

  • „We can lose a node and nobody notices.“

  • „Scaling is just config — no manual interventions.“