7.4 Virtual Environments

Definition of virtual environments

What is a Virtual Environment?
A virtual environment is a software‑based representation of computing resources that allows multiple operating systems or systems to run independently on the same physical hardware.

Virtual environments separate software from physical hardware, improving flexibility, security, and efficiency.

7.4.1 Virtual environment components

Virtual Machines (VMs)
Virtual machines are software‑based computers that behave like physical machines.

Clients:
  • Virtual PC
  • Virtual switch
  • Virtual router
Servers: Virtual servers host applications, storage, or network services.
Hypervisors
A hypervisor manages and allocates physical hardware resources to virtual machines.
  • Type 1 (bare‑metal) – runs directly on hardware
  • Type 2 (hosted) – runs on top of an operating system

7.4.2 Key features of virtual environments

Virtual Environment Features
  • Increased security through isolation
  • Managed execution of software
  • Sharing of physical resources
  • Aggregation of multiple systems
  • Emulation of hardware and systems
  • Isolation between environments
  • Portability between hardware platforms

7.4.3 Benefits of virtual environments

Advantages of Virtualisation
  • Cost effectiveness for large environments
  • Easy centralised management
  • Improved system resilience and availability
  • Potentially lower carbon footprint
  • Improved disaster recovery options
  • Better testing and development environments
  • Support for education and training

7.4.4 Drawbacks of virtual environments

Disadvantages of Virtualisation
  • Additional hardware resource overhead
  • Slower execution compared to physical systems
  • Potentially misleading performance measurements