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Kubernetes is Not the New VM:
Choosing the Right Abstraction for Modern
Infrastructure
@CloudStack European User Group, The Hague, NL
Stoil Stoilov, DevOps Engineer, StorPool
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“Ladies and gentlemen… according to the internet, infrastructure engineers are no longer needed.”
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Infrastructure Evolution
Is Not Replacement — It Is Layering Evolution
Physical servers
Virtualization
Cloud / Orchestration
Containers
Kubernetes
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From Bare Metal to Kubernetes
Tracing the structural evolution of modern computing layers
K8s Node VM
Containers / Pods
A Cube in 1996
Physical Host
A Kube in 2026
Physical Host
Virtualization
Kubernetes Control Plane
Physical Host
Virtualization
VM 1 VM 2 VM 3
K8s Node VM
Containers / Pods
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Bare Metal world
Rigid infrastructure created significant operational bottlenecks

Slow Provisioning
Weeks or months spent on hardware procurement, shipping,
and manual racking before a single line of code could run.

Resource Silos
Hardware was locked to specific apps. One server might
sit at 5% utility while another crashed from over-utilization.

Manual Failover
Hardware failure meant immediate downtime. Recovery
required physical intervention or complex, manual clustering.

Hard Scaling
Scaling required buying new physical assets. There was no
"elasticity"—you either over-provisioned or ran out of capacity.
Bare metal represents maximum control but carries the burden of maximum operational responsibility.
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Virtualization Changed Infrastructure Forever
Decoupling software from hardware created new paradigms of efficiency

Resource Pooling
Aggregating physical
resources to serve
multiple VMs efficiently.

Isolation
Sandboxing environments
to ensure security and
stability across
workloads.

High Availability
Continuous operation
through automated
failover and redundancy.

Scalability
Rapidly adjusting
resources to meet
changing demand without
physical limits.
Virtualization remains the cornerstone of modern data center orchestration and cloud economics.
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Cloud Changed Expectations
From Manual Operations to API-Driven Agility

API-Driven
Infrastructure
Developers gained direct
control over infrastructure
through code, bypassing
manual ticketing and long lead
times.

Elasticity & Dynamic
Load
The shift to dynamic loads
meant infrastructure had to
scale instantly. CloudStack was
a pioneer in this orchestration.

Self-Service Culture
Empowered users to provision
resources on-demand,
drastically changing
expectations for speed and
reliability.
CloudStack emerged as one of the first orchestration platforms to manage this new paradigm of scale and automation.
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Containers and Kubernetes
Containers solved packaging
• application packaging
• portability
• dependency consistency
• faster deployment
Kubernetes solved orchestration
• orchestration
• scheduling
• elasticity
• self-healing
• distributed operations
Hardware
Hypervisor
VM
Guest OS
Application
Hardware
OS Kernel
Container
Runtime
Containers
Application
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Operational Overhead
Layering abstracts complexity for developers but increases overall operational burden.
Software Development Focus Infrastructure Operations Focus
Applications & Services
Kubernetes / Orchestration
Container Runtime & OS
Virtualization / Hypervisor
Bare Metal / Hardware
Cleaner Abstraction
Developers only interact with
high-level APIs. Underlying
complexity is hidden. Operational Overhead
Infrastructure engineers must
manage interconnects, security,
and updates for 5+ layers.
Each layer adds management overhead
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Mapping the Infrastructure Landscape
Scalability
Complexity
Q1: Legacy Complexity
High management overhead with limited scaling.
Traditional bare-metal silos that are difficult to
automate and slow to update.
Q2: Cloud Native Powerhouse
Maximum scalability but extreme operational
complexity. Multi-layer stacks requiring expert
orchestration and constant patching.
Q3: Simplified Operations
Lean abstractions for stable workloads. Focus on
developer productivity where massive scale isn't the
primary driver.
Q4: Strategic Efficiency
The "Sweet Spot": High scalability with abstracted
overhead. Developers interact with APIs while infra
is managed as a service.
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Modern Infrastructure Is Hybrid by Design
Evolution through layering, not replacement
Hybrid Coexistence
Most production environments
combine multiple models.
Kubernetes did not replace
virtualization; it became another
layer on top.
Unified Foundation
Storage and networking layers are
shared underneath regardless of
whether the workload is a VM or a
Container.
Workload-Centric
Designing around behavior: AI on
bare metal, DBs on VMs, and APIs
in Kubernetes clusters running on
VMs.
Kubernetes / Orchestration Layer
Virtualization / Hypervisor Layer
Shared Infrastructure: Distributed Storage & SDN
 
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The Real Question Is Not
“VMs or Kubernetes?”
What does the workload need?
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Hyperconverged (HCI)
Characteristics
● Compute and storage scale together
● Unified lifecycle management & simplicity
● Easier deployment; fewer layers
Good Fit For
● General-purpose clouds & mixed workloads
● Smaller operational teams & Edge
Tradeoff
Less independent scaling flexibility
Disaggregated
Characteristics
● Storage and compute scale independently
● Workload-specific tuning & optimization
● Higher flexibility at scale
Good Fit For
● Specialized high-performance workloads
● Very large cloud platforms
Tradeoff
Higher complexity; more networking/layers
The Infrastructure Trade Off Principle
Every architecture optimizes for one factor (e.g., simplicity) while sacrificing another (e.g., flexibility).
Architecture is a balancing act between performance, flexibility, scalability, and overhead.
HCI vs Disaggregated Infrastructure
Simplicity vs specialization
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Kubernetes vs Virtual Machines
Choosing the right model for the workload
Virtual Machines
Strengths
● Strong isolation & mature tooling
● Operational simplicity
● Predictable performance
● Easier troubleshooting
Common Fits
● Enterprise apps & Databases
● Monolithic systems
● Stable workloads
● Smaller operational teams
Kubernetes
Strengths
● Orchestration & Elasticity
● Horizontal scaling
● Rapid deployments & Self-healing
● Distributed applications
Common Fits
● Microservices & APIs
● AI inference platforms
● CI/CD-heavy environments
"Does this workload benefit from orchestration and elasticity?"
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A Workload That Naturally Fits Kubernetes
Characteristics
● Horizontally scalable
● Bursty traffic
● Distributed by nature
Why Kubernetes Fits Well
● Rapid scaling
● Orchestration
● Fault isolation
Infrastructure Priorities
● East-west traffic
● Observability
● Elasticity
Kubernetes works best when the app is distributed by nature.
Cloud-native by design
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A Workload That May Not Naturally Fit Kubernetes
Characteristics
● Vertically scaled workers
● Long-running tasks
● Low user concurrency
Operational Reality
● Queue-based scheduling
● Distributed over time
● Vertically intensive tasks
Infrastructure Priorities
● Large VMs or Bare Metal
● Predictable performance
● Vertical scalability
Horizontal task distribution ≠ horizontal scaling
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AI Workloads Bring Back Hardware Awareness
Modern AI
● Massive parallel processing
● Large datasets
● Resource hungry
Implications
● Locality matters
● Huge east-west traffic
● Latency
Architectural
● Storage requirements
● Network requirements
● Nodes topology
AI brought back physical reality
AI workloads are reminding us that infrastructure abstractions never removed the importance of hardware behavior.
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Kubernetes Is More Capable Than Many Assume
Kubernetes CAN support:
● stateful applications
● databases
● distributed storage
● high availability
● cluster-aware systems
● object storage
● operators
● persistent volumes
Cloud-Native Characteristics
● horizontally scalable
● failure-tolerant
● orchestration-aware
● externally managed state
● distributed by design
● API/service-oriented
Kubernetes is more than a container runner; it's a distributed systems platform.
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The Philosophical Shift
Modern infrastructure is hybrid by
necessity
The future is not choosing one abstraction.
The future is understanding
which abstraction fits the workload best.
“hybrid
application aware
infrastructure”
BARE METAL VMs Containers Kubernetes
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Orchestrating Kubernetes-Ready Clouds
CloudStack
 Multi-tenancy
 CSI
Integrations
Hybrid
Coexistence

Physical Infrastructure
Hypervisor Layer
Apache CloudStack Orchestration
Virtual Machines
Kubernetes Clusters
Containers / Applications
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HCI node
Bare metal
Unified Infrastructure Requires Unified Storage
kubelet
Container Engine
Pod
Pod Pod Pod
Pod Pod
CSI Hypervisor
VM VM VM
cloudstackagent
VM VM VM
Worker node (VM)
v
kubelet
CSI
Container Engine
Pod
Pod Pod Pod
Pod Pod
Pods
Container
Storage
Interface
Unified
Storage
Orchestration
CloudStack
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Key takeaways
Decoupling software from hardware created new paradigms of efficiency

Layering
Infrastructure didn’t
evolve through
replacement

Complexity
Kubernetes is extremely
capable, but comes at a
cost

Workload
Behavior matters more
than technology trends

Trade Offs
There are no universal
answers
Virtualization remains the cornerstone of modern data center orchestration and cloud economics.
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Good infrastructure follows
workload behavior.
Great infrastructure understands
operational context.
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Questions?
“Or has AI already answered them?”
linkedin.com/in/stoil-stoilov/