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54.Virtualizations_and_Cloud_Part1

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Virtual Servers

  • While Cisco is renowned for its networking devices (e.g., routers, switches, and firewalls), they also produce hardware servers, such as the UCS (Unified Computing System).
  • Major hardware server vendors include:
    • Dell EMC
    • HPE
    • IBM

Servers Before Virtualization

  • Pre-Virtualization Setup:

    • Each physical server was dedicated to a single operating system (OS).
    • Within this OS, applications like web servers, email servers, or database servers ran independently.
    • A separate server was required for each service (e.g., one for the web server, one for the email server, and so on).

  • Challenges:

    • High costs due to the need for multiple physical servers.
    • Excessive consumption of space, power, and cooling resources.
    • Under-utilized hardware resources (CPU, RAM, storage, etc.).

Virtualization: Type 1 Hypervisor

  • What is Virtualization?

    • Virtualization breaks the one-to-one hardware-to-OS relationship.
    • Multiple OS instances, called Virtual Machines (VMs), can run on a single physical server.
    • A Hypervisor manages the allocation of hardware resources (e.g., CPU, RAM) among VMs.

  • Key Features:

    • Also known as a Virtual Machine Monitor (VMM).
    • Type 1 Hypervisor:
      • Runs directly on hardware (also called “bare-metal” or “native” hypervisor).
      • Examples: VMware ESXi, Microsoft Hyper-V.
      • Primarily used in data center environments.

Virtualization: Type 2 Hypervisor

  • Type 2 Hypervisor:

    • Runs as an application on an existing operating system.
    • Examples: VMware Workstation, Oracle VirtualBox.

  • Key Concepts:

    • The underlying OS on the hardware is the Host OS.
    • The OS running inside a VM is the Guest OS.
    • Commonly used for personal devices (e.g., running Windows on macOS or Linux).

Benefits of Virtualization

  1. Partitioning:

    • Run multiple OS instances on a single physical machine.
    • Divide system resources among VMs efficiently.

  2. Isolation:

    • Fault and security isolation between VMs.
    • Advanced resource controls maintain performance.

  3. Encapsulation:

    • Save a VM’s entire state as files, enabling easy migration or duplication.

  4. Hardware Independence:

    • Migrate VMs to any compatible physical server.

Virtual Networks

  • VMs connect to each other and external networks via a Virtual Switch (vSwitch), which runs on the hypervisor.
  • Key vSwitch capabilities:
    • Operates as access ports or trunk ports.
    • Supports VLANs for Layer 2 isolation.
    • Interfaces connect to the server’s physical NIC(s) for external communication.

Introduction to Cloud Computing

Traditional IT Infrastructure

  1. On-Premises:

    • Servers, networking devices, and other infrastructure reside on company property.
    • Equipment is owned, maintained, and powered by the company.

  2. Co-location:

    • Data centers lease space for customers to house their infrastructure.
    • While the data center provides the environment (power, cooling, etc.), customers manage their hardware.
  • Cloud Services offer a scalable alternative, with providers like AWS leading the charge.

Cloud Computing Models and Characteristics

Key Definition

  • NIST Special Publication 800-145 outlines cloud computing’s characteristics, service models, and deployment models.

Five Essential Characteristics of Cloud Computing

  1. On-Demand Self-Service:

    • Users can provision or discontinue services without provider interaction.

  2. Broad Network Access:

    • Accessible through the Internet or private WAN via various devices.

  3. Resource Pooling:

    • Resources are shared and allocated dynamically to customers from a pooled infrastructure.

  4. Rapid Elasticity:

    • Resources can scale up or down quickly, appearing nearly infinite.

  5. Measured Service:

    • Usage is metered, enabling pay-as-you-go pricing models.

Three Service Models of Cloud Computing

  1. Software as a Service (SaaS):
    • Complete applications hosted by the provider.
    • Example: Microsoft Office 365.

  1. Platform as a Service (PaaS):
    • Developers build applications using tools provided by the provider.
    • Examples: AWS Lambda, Google App Engine.

  1. Infrastructure as a Service (IaaS):
    • Provides raw compute, storage, and networking resources.
    • Examples: Amazon EC2, Google Compute Engine.

Cloud Deployment Models

Overview

  • Public perception often equates “cloud” with Public Cloud, but there are other models:
  1. Private Cloud:
    • Dedicated to a single organization.
    • Can be on-premises or hosted by third-party providers like AWS (e.g., for U.S. DoD).

  1. Community Cloud:
    • Shared by a specific group of organizations with common goals or compliance needs.
    • Least common deployment model.

  1. Public Cloud:
    • Hosted by providers like AWS, Azure, or Google Cloud.
    • Open to general public or large user groups.

  1. Hybrid Cloud:
    • Combines two or more deployment models.
    • Example: A private cloud offloads to a public cloud during high demand.

Benefits of Cloud Computing

  • Cost Savings:
    • Reduces capital expenses for hardware and data center setup.
  • Global Scale:
    • Services deploy quickly in regions close to users.
  • Speed and Agility:
    • Resources provisioned on demand within minutes.
  • Productivity:
    • Eliminates time-consuming tasks like hardware installation.
  • Reliability:
    • Simplifies backups and disaster recovery with data mirroring across locations.

Connecting to Public Clouds

Graph View

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