Overview
This session introduces the foundational concepts of virtualization, explaining what it is, its historical context, and the compelling benefits it offers in modern IT environments.
Key Topics
- What is Virtualization?
- Definition: The creation of a virtual (rather than actual) version of something, such as an operating system, a server, a storage device, or network resources.
- Host vs. Guest: Clearly defining the physical machine (Host) and the encapsulated environment (Guest).
- Benefits of Virtualization
- Server Consolidation: Reducing the physical server count, leading to lower power consumption, cooling costs, and physical space requirements.
- Isolation: Ensuring that applications running on one VM cannot interfere with others, enhancing security and stability.
- Portability and Flexibility: The ability to move entire operating system environments easily between different physical hardware.
- Rapid Provisioning: Quickly deploying new environments compared to procuring and setting up physical hardware.
- Use Cases
- Development and Testing Environments: Allowing developers to test software across multiple OS configurations without dedicated hardware.
- Server Migration and Disaster Recovery: Simplifying migration efforts and improving recovery time objectives (RTO).
- Cloud Computing Infrastructure: Virtualization is the bedrock of public and private cloud services.
- A Brief History
- Tracing the origins from mainframes to modern x86 virtualization extensions (Intel VT-x / AMD-V).
- Advanced Concept: Full Hardware Emulation vs. Hardware-Assisted Virtualization: Explain the difference between early emulation (like Bochs) and modern virtualization relying on Intel VT-x or AMD-V, which use hardware features to trap privileged instructions, dramatically boosting performance.
Lab/Assessment
Research and compare three different virtualization solutions available today (e.g., VMware vSphere/ESXi, KVM, Microsoft Hyper-V). Your comparison should cover architecture type (Type 1/Type 2), licensing model, and primary market/use case.
Lab Extension: Bare-Metal vs. Hosted Examples
- Type 1 Example Focus: Investigate how ESXi manages direct access to the physical HBA (Host Bus Adapter) for storage paths, a key performance advantage.
- Type 2 Example Focus: Discuss the impact of the Host OS kernel scheduler on VM latency when using VirtualBox.