Comprehensive Notes on Data Centers and Virtualization

Data Center and Virtualization

Learning Objectives

  • Understand data centers.

  • Discuss cloud data centers.

  • Understand virtual data centers.

  • Explain the difference between virtual data centers and traditional data centers.

  • Explain virtualization techniques.

  • Describe the benefits, advantages, and disadvantages of virtualization.

  • Understand the types of virtualization.

  • Explain the hypervisor.

  • Describe the types of hardware virtualization.

Data Center

  • Data centers are centralized locations for computing and networking equipment.

  • Purpose: collecting, storing, processing, distributing, or allowing access to large amounts of data.

  • Provide services like:

    • Data storage

    • Backup and recovery

    • Data management

    • Networking

Cloud Data Center

  • A remote version of a data center located away from a company's physical premises.

  • Accessed through the internet.

  • Hardware is managed by the cloud company, often with a third-party managed services provider.

  • Clients run applications and manage data within a virtual infrastructure on cloud servers.

Purpose of a Data Center

  • Centralizes an organization's IT operations and equipment for storing, processing, and disseminating data and applications.

  • Used by:

    • Government agencies

    • Educational bodies

    • Telecommunications companies

    • Financial institutions

    • Retailers

    • Online information and social networking services (e.g., Google, Facebook)

Data Center Roles

  • Data Center Project Manager

  • Compliance Officer

  • Cybersecurity Specialist

  • Data Center Technician

  • Cloud Architect

Cloud vs. Data Center

  • Data Center: On-premise hardware.

  • Cloud: Off-premise computing.

  • Data is stored in the public cloud, while data centers store data on your own hardware.

  • SaaS Defined: A solution hosted and maintained by a third-party.

  • On-Premise Defined: A solution hosted in-house and usually supported by a third-party.

  • Off-Premise Defined: A solution hosted by a third-party and usually supported by a different third-party.

Virtual Data Center (VDC)

  • A virtualized pool of cloud infrastructure resources.

  • Includes computing, memory, storage, and bandwidth.

  • Designed for enterprise business needs.

  • Also known as a software-defined data center.

  • More cost-effective, flexible, and practical than on-prem data centers.

  • Uses cloud-based resources to create a scalable infrastructure aligned with operational needs.

  • Offers the same capabilities as a physical counterpart.

    • Servers

    • Processing power (CPU)

    • Storage clusters (RAM and disk space)

    • Networking components and bandwidth

  • Provides computing capabilities for:

    • File sharing

    • Email operations

    • Productivity apps

    • CRM and ERP platforms

    • Database operations

    • Big data

    • AIOps and machine learning

    • Communication and collaboration apps

  • Allows adding or removing capacity without hardware setup or takedown.

  • Components run on the provider's virtual machine (VM).

  • Client pays on a pay-as-you-use basis.

Reasons for Deploying a VDC

  • Flexible and scalable infrastructure.

  • Shorter time-to-market and idea-to-cash cycles.

  • High availability.

  • Higher levels of IT setup customization.

  • Cost reductions (no rental, power, cooling, maintenance, or hardware costs).

Benefits of a Virtual Data Center

  • Easily Scalable Infrastructure

  • On-Demand Resource Provisioning

  • Cost-Saving Opportunities

  • Simplified, Centralized Management

  • Lack of Downtime

  • More Business Agility

  • Simpler Security

Virtual Data Centers and Cloud Computing

  • Falls under the Infrastructure as a Service (IaaS) delivery model of cloud computing.

  • Enables a company to request physical components and form a data center with:

    • Server racks.

    • Storage hardware.

    • Networking equipment.

    • Software and hardware backups.1

  • Most IaaS providers offer services such as:

    • Performance monitoring

    • Network security

    • Firewall management

    • Data redundancy services

Difference Between Virtual and Traditional Data Centers

Feature

Virtual Data Center

Traditional Data Center

Location

Not bound to any physical location. Multiple virtual data centers can coexist in one physical data center; a single server can span multiple physical data centers.

Always bound to one physical location. Migration is costly and expensive.

Spending model

Operating expenses (OpEx) model: companies consume IT services on a pay-as-you-go pricing scheme.

Capital expenditure (CapEx): organizations pay upfront costs to acquire IT infrastructure.

Compute complexity

  • Deploys resizable virtual servers based on workload demands.

  • Deploys a mixture of storage technologies and increments on demand.

  • Relies on software-defined networking (SDN) and virtual switches to scale up/down network capacity. |

  • Deploys servers that rely on fixed CPUs, memory, and storage to run workloads.

  • Requires evaluation and estimation of storage technologies and negotiation with multiple vendors.

  • Requires planning for additional networking gear (switches, routers, cabling) when scaling up. |
    | Resource provisioning | Relies on software to orchestrate the provisioning, configuration, and management of virtualized resources. | Relies on IT administrators to rack and stack data center equipment. |

Virtualization

  • Creation of a virtual version of:

    • Server

    • Desktop

    • Storage device

    • Operating system

    • Network resources

  • Technique to share a single physical instance of an application or resource among multiple organizations or tenants.

  • Assigning a logical name to a physical resource and providing a pointer to that resource when demanded.

  • Multiple operating systems and applications can run on the same machine and hardware simultaneously.

  • Increases utilization and flexibility of hardware.

Virtualization Benefits

  • Cost-effective, hardware-reducing, and energy-saving technique.

  • Provides a virtual environment for applications, storage, memory, and networking.

  • Example: Running Windows OS on a virtual machine on top of Linux OS.

  • The machine on which the virtual machine is created is known as host machine.

  • Virtual machine is referred to as a guest machine.

APP
APP
APP

Binaries/ Libraries
Binaries/ Libraries
Binaries/ Libraries

Guest OS
Guest OS
Guest OS
Hyperviser

Host OS

Server Hardware

Virtualization
Causes for Virtualization Demand

  1. Increased performance and computing capacity: Computers are capable to support virtualization technologies.

  2. Underutilized hardware and software resources: Resources can be used for other works after office hours.

  3. Lack of space: Companies need more space which can be solved by virtualization.

  4. Greening initiatives: Reducing the number of servers reduces the impact of cooling and power consumption.

  5. Rise of administrative costs: Power consumption and cooling costs are high.

Benefits of Virtualization

  1. More flexible and efficient allocation of resources.

  2. Enhance development productivity.

  3. Lowers the cost of IT infrastructure.

  4. Remote access and rapid scalability.

  5. High availability and disaster recovery.

  6. Pay per use of the IT infrastructure on demand.

  7. Enables running multiple operating systems.

Advantages of Virtualization

  1. Increased security: Control the execution of a guest in a transparent manner.

  2. Managed execution: Provides sharing, aggregation, emulation, isolation, etc.

  3. Portability: User works can be safely moved and executed on top of different virtual machines.

Disadvantages of Virtualization

  1. Performance degradation: Increased latencies due to abstraction layer.

  2. Inefficiency and degraded user experience: Some host features cannot be exposed by the abstraction layer.

  3. Security holes and new threats: New forms of phishing; malicious programs can preload themselves.

Virtualization Technology Examples:

  • Xen

  • VMware

Types of Virtualization

  1. Storage Virtualization

  2. Network Virtualization

  3. Desktop Virtualization

  4. Application Virtualization

  5. Server Virtualization

  6. Data Virtualization

  7. Software Virtualization

  8. Memory Virtualization

Some Types of Virtualization

  1. Storage virtualization: Pooling physical storage from multiple devices into a single device.

  2. Network virtualization: Management and monitoring of an entire computer network as a single entity.

  3. Desktop virtualization: Simulate a workstation load to access a desktop from a connected device remotely or locally.

  4. Application server virtualization: Abstracts a collection of application servers that provide the same services as a single virtual application server.

  5. Server virtualization: Masking of server resources. Physical server is divided into multiple virtual servers.

  6. Data Virtualization: Data is collected from various sources and managed at a single place.

  7. Software virtualization: Abstract the software installation procedure and create virtual software installations.

    • Virtualized software is an application that will be "installed" into its own self-contained unit.

    • Example: VMware software, virtual box etc.

Advantages of Software Virtualization:

  1. Client Deployments Become Easier:
    Install virtual software by copying a file to a workstation or linking a file in a network.

  2. Easy to manage:
    Update at one place and deploy the updated virtual application to all clients.

  3. Software Migration:
    Migration becomes easier with a virtualized software environment.

Memory Virtualization: Allows networked servers to share a pool of memory to overcome physical memory limitations.

Hardware Virtualization

  • Creating a virtual machine over an existing operating system and hardware

  • The machine where VM is created: host machine

  • The VM: guest machine

  • Managed by a hypervisor (virtual machine manager).

Hypervisor

  • Software or firmware that manages virtual machines.

  • Also known as Virtual Machine Manager.

  • Two types:

    • Type 1: Executes on bare system (without an intervening operating system).

      • Examples: LynxSecure, RTS Hypervisor, Oracle VM, Sun XVM Server, VirtualLogic VLX

    Type 1 Hypervisor

Guest OS
Guest OS
Guest OS

Hypervisor

System Hardware

    • Type 2: A software interface that emulates the devices with which a system normally interacts.

      • Examples: Containers, KVM, Microsoft Hyper V, VMWare Fusion, Virtual Server 2005 R2, Windows Virtual PC and VMWare workstation 6.0

    Type 2 Hypervisor

Guest OS
Guest OS
Guest OS

Hypervisor

Host Operating System

Types of Hardware Virtualization

  1. Full Virtualization

  2. Emulation Virtualization

  3. Paravirtualization

  • Full Virtualization: The underlying hardware is completely simulated.

    • Guest software does not require any modification to run.

    Guest
Kernel
Software

Host
Kernel
Software

Virtual Environment
VM Control

Type 1 Hypervisor

  • Emulation Virtualization: The virtual machine simulates the hardware and becomes independent of it.

    • The guest operating system does not require modification.

    Guest
Kernel
Software

Host
Kernel
VM Software

System Hardware

  • Paravirtualization: The hardware is not simulated.

    • The guest software runs in its own isolated domain.

    Guest
Kernel

Virtual Environment

Host
VM Kernel
Software
VM Control

System Hardware

  • VMware vSphere is a highly developed infrastructure that offers a management infrastructure framework for virtualization.

  • It virtualizes the system, storage, and networking hardware.