Client Side Virtualization 4.2

Virtualization History

Established in the '60s, but VMware’s 1999 x86 breakthrough made it mainstream. It slashes costs, simplifies management, and packs serious perks.

Traditional Computing Model

A single OS controls all hardware. This model is inefficient as hardware often sits idle. Companies want better utilization, especially for expensive servers.

Virtualization

Improves efficiency by running multiple OSes (VMs) on one machine. Each VM is independent and runs its own applications, increasing hardware utilization.

Type 2 Hypervisor

Runs on top of a host OS to manage guest VMs. Examples include VMware Workstation, Oracle VM VirtualBox, Parallels Desktop, and QEMU.

Container Virtualization

Lightweight alternatives to VMs, sharing the host OS but isolating apps and dependencies for portability and security. They reduce overhead and licensing costs.

Containers vs. Virtual Machine

Containers = speed, size, and efficiency champs. VMs play well with any hypervisor; containers stick to their OS family, rock modular apps and lightning-fast scaling.

Virtualization Security

Physical hardware security is critical—VMs and containers live on it. One slip-up can spread like wildfire. Document virtual setups like real gear, and never mix internet-facing with internal services.

Sandbox virtualization

Isolated environment for safe software testing and development without risking production systems.

Application virtualization

Apps are run virtually to cut licensing costs, boost access, and simplify maintenance.

Legacy software access

Allows older applications to run on modern systems through virtual environments.

Cross-platform virtualization

Enables apps to run on different operating systems than originally designed for.

Hardware optimization

Improves hardware efficiency by utilizing idle CPU, RAM, and storage for multiple tasks.

Host machine

Physical server with shared hardware resources (HDD, RAM, CPU, NIC) for virtual environments.

Hypervisor

Software layer managing VMs and mediating between hardware and virtual OSes.

Virtual machine

Software-based computer that functions like a physical one, running its own OS and apps.

Virtual hard disk (VHD)

File-based simulated hard drive used by a VM.

vSwitch

Software that routes data packets between virtual machines.

vRouter

Virtualized router software that enables flexible IP routing independent of physical devices.

Virtual firewall application (VFA)

Software firewall that monitors and filters virtual network traffic within VMs.

What is VM escaping in virtualization security?

Type of security breach where a program or attacker breaks out of a virtual machine and gains access to the host system or other VMs

What is a rogue VM?

Avirtual machine that was created without authorization, often bypassing security controls

Why is rogue VM a security risk?

Consumes system/network resources, Bypasses monitoring, Runs malicious or unpatched software.

What is a third-party virtual machine?

A virtual machine image or appliance created by an external vendor or developer, not by your own IT team

What are third-party virtual machine risks?

Malware-infected or misconfigured images, Lack of patching or vendor support, Compatibility or licensing issues

Type 1 Hypervisor

Also called bare metal because it installs directly onto hardware without a host OS. Acts as the primary OS. Examples: VMware ESXi, Microsoft Hyper-V Server.

Type 1 vs Type 2 Equivalence

Functionally similar in managing VMs, but differ in how they access hardware. Type 2 depends on host OS, Type 1 runs natively.

VM Overhead

Each virtual machine needs its own full OS, which increases storage, memory, and processing overhead.

Containers Isolation

Each container is self-contained and unaware of other containers unless explicitly configured to communicate.

Container Portability

Containers don’t include a full OS, making them lightweight, fast to transfer, and highly portable between systems.

Single Host OS for Containers

All containers on a host share a single operating system kernel, which reduces overhead but limits OS flexibility.

Container Dependency on Host OS

Containerized applications must be compatible with the host OS; they rely on its kernel and services to function.

Docker & Container Compatibility

A Docker container must be compatible with the host OS and Docker version; you can’t always run the same container across different versions without issues.