TOPIC CONTAINERS
Containers vs VMs isolation without a whole OS
IN 10 SECONDS
Virtual Machines bundle a full guest OS with virtual hardware via a hypervisor. Containers share the host kernel and isolate processes using kernel namespaces and cgroups, making them lightweight.
GOTCHA Since containers share the host kernel, a security vulnerability in the host kernel can compromise all containers running on that machine.
HOW ISOLATION LEVEL FLOWS
01 VM boot hypervisor boots a virtual BIOS, loads guest kernel, and initializes system services (minutes).
02 Container boot host kernel executes the container entrypoint process in isolated namespaces directly (milliseconds).
03 Virtual Disk VMs allocate large fixed-disk virtual files; containers stack thin layered filesystems.
04 Resource share VMs freeze RAM; containers allocate resource limits dynamically.
POKE IT YOURSELF
docker info — check host kernel and container platform info
uname -a — check host kernel release name inside container
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