Why you wouldn’t run hundreds of containers directly on bare metal:
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Single point of failure → if the kernel or hardware dies, everything dies.
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Kernel risk → one bad kernel update could wipe out hundreds of containers at once.
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Hard to isolate performance issues → containers can still compete for CPU/memory in messy ways.
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Hard to scale → bare metal doesn’t autoscale like cloud resources do.
Instead, the smart way is:
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Use virtualization (VMs) or cloud-managed instances (like AWS EC2, Google Compute Engine, etc.).
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Run maybe 20–50 containers per VM (depends, of course).
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If a VM has a problem → only a small chunk of containers die, not everything.
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Plus, cloud infra can autoscale, replace bad VMs, load-balance, etc.
Real-world setup:
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VMs are the „crumple zones“ protecting your container workloads.
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Kernel upgrades, patches, crashes → only affect one small batch at a time.
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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:
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Every kernel update is a potential mass-extinction event.
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Every hardware issue (disk, CPU, RAM) can kill hundreds or thousands of services at once.
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Scaling is painful and manual.
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Disaster recovery is slow and risky.
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Monitoring and troubleshooting become nightmares — one crash = massive chaos.
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Security risks are higher because everything is jammed together and hard to isolate cleanly.
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You will be constantly firefighting instead of building things.
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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:
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❌ „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:
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„We spread containers over many small instances.“
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„We use managed services (EKS, GKE, ECS).“
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„We have automated health checks, rolling updates, blue/green deployments.“
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„We can lose a node and nobody notices.“
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„Scaling is just config — no manual interventions.“