VM's vs Containers
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VIRTUAL MACHINES (VMs) 🖥️ VS CONTAINERS 📦
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TABLE – Quick Comparison
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Feature | Virtual Machines (VMs) | Containers
--------------------|----------------------------------|-------------------------
Architecture | Hardware → Host OS → Hypervisor | Hardware → Host OS → Container Engine
| → Guest OS → App | → App
OS | Full OS per VM | Shared host OS kernel
Resource Usage | Heavy (CPU/RAM per OS) | Lightweight
Startup Time | Slow (minutes) | Fast (seconds)
Isolation | Strong (separate OS) | Moderate (shared kernel)
Portability | Large images (GBs) | Small images (MBs)
Use Cases | Multiple OS types, legacy apps, | Microservices, CI/CD, rapid scaling
| strong security isolation |
Example Tools | VMware, VirtualBox, Hyper-V | Docker, Podman, containerd
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ARCHITECTURE – Side-by-Side Stack
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VMs: | Containers:
┌──────────────────────────┐ | ┌──────────────────────────┐
│ Application │ | │ Application │
├──────────────────────────┤ | ├──────────────────────────┤
│ App Dependencies │ | │ App Dependencies │
├──────────────────────────┤ | ├──────────────────────────┤
│ Guest OS (per VM) │ | │ Container Runtime Env │
├──────────────────────────┤ | ├──────────────────────────┤
│ Hypervisor │ | │ Container Engine │
├──────────────────────────┤ | ├──────────────────────────┤
│ Host OS │ | │ Host OS │
├──────────────────────────┤ | ├──────────────────────────┤
│ Hardware │ | │ Hardware │
└──────────────────────────┘ | └──────────────────────────┘
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STARTUP FLOW – Layer-by-Layer
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VMs: Containers:
[1] Start VM [1] Start container
[2] Host OS running [2] Host OS running
[3] Hypervisor allocates CPU/RAM/devices [3] Container engine allocates CPU/RAM namespaces
[4] Boot full Guest OS [4] Setup file system layers
[5] Start OS services [5] Setup networking (bridge/veth)
[6] Launch application [6] Launch application
Boot Time: Minutes Boot Time: Seconds
Resource Cost: High Resource Cost: Low
Isolation: Strong Isolation: Moderate
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RULE OF THUMB:
- Use VMs for full OS isolation, multiple OS types, and legacy/secure workloads.
- Use Containers for lightweight, fast, and scalable app deployments.
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