Nothing Special   »   [go: up one dir, main page]
Scribd Logo
Upload

Welcome to Scribd!

  • 208 views

    A Virtualisation Case Study

    Uploaded by

    Kingsley Gaius
    This document discusses virtualization concepts and types including a case study on hosted desktop virtualization. It defines virtualization as dividing physical hardware resources into separate virtual machines. The major types discussed are paravirtualization, full virtualization with and without hardware assistance, and hosted virtualization. Advantages include increased hardware utilization, reduced costs, easier management, and business flexibility.

    Copyright:

    Attribution Non-Commercial (BY-NC)
    Download as PPTX, PDF, TXT or read online from Scribd

    A Virtualisation Case Study

    Uploaded by

    Kingsley Gaius
    208 views25 pages
    This document discusses virtualization concepts and types including a case study on hosted desktop virtualization. It defines virtualization as dividing physical hardware resources into separate virtual machines. The major types discussed are paravirtualization, full virtualization with and without hardware assistance, and hosted virtualization. Advantages include increased hardware utilization, reduced costs, easier management, and business flexibility.

    Original Description:

    Original Title

    Virtualization

    Copyright

    © Attribution Non-Commercial (BY-NC)

    Available Formats

    PPTX, PDF, TXT or read online from Scribd

    Did you find this document useful?

    Is this content inappropriate?

    This document discusses virtualization concepts and types including a case study on hosted desktop virtualization. It defines virtualization as dividing physical hardware resources into separate virtual machines. The major types discussed are paravirtualization, full virtualization with and without hardware assistance, and hosted virtualization. Advantages include increased hardware utilization, reduced costs, easier management, and business flexibility.

    Copyright:

    Attribution Non-Commercial (BY-NC)
    Download as PPTX, PDF, TXT or read online from Scribd
    Download as pptx, pdf, or txt
    208 views25 pages

    A Virtualisation Case Study

    Uploaded by

    Kingsley Gaius
    This document discusses virtualization concepts and types including a case study on hosted desktop virtualization. It defines virtualization as dividing physical hardware resources into separate virtual machines. The major types discussed are paravirtualization, full virtualization with and without hardware assistance, and hosted virtualization. Advantages include increased hardware utilization, reduced costs, easier management, and business flexibility.

    Copyright:

    Attribution Non-Commercial (BY-NC)
    Download as PPTX, PDF, TXT or read online from Scribd
    Download as pptx, pdf, or txt
    of 25

    A Virtualisation case study

    Content
     Virtualization – a brief introduction
     Concepts of virtualization
     Virtualization definition
     Virtualization types
     Virtualisation – a case study
     Disadvantages
     Advantages
     Conclusion
     References
    Abbreviations
    • SW - Software
    • OS – Operating system
    • VM – Virtual Machine
    • HW – Hardware
    • VMM – Virtual Machine Monitor
    • TCO – Total Cost of Ownership
    • CAPEX – Capital Expenditure
    • OPEX – Operational Expenditure
    Virtualisation – a brief introduction
    • In 1960, first Implemented by IBM to separate mainframes into partitions of
    logical virtual machines

    • The partitions allowed mainframes to multitask


    (run multiple applications same time)

    • 1990 to 1980, cheaper x86 servers and desktops almost replaced virtualization

    • Physical servers Increased and resulted in an increased in:


    CAPEX - On going capital expenditure
    OPEX - On going operational expenditure

    • In 1999 VMware introduced a virtualization solution that transforms a single x86


    server into multiple virtual servers
    Concepts in virtualization
    1. Host OS: the resident OS that host other OSs or VMs
    2. Guest OS: OS or VM installed in a host OS
    3. Hypervisor : also calls Virtual Machine Monitor (VMM)
     SW that allows multiple OS to share a single HW
     Allocates resources and memory to each OS
     Ensures there is no conflict
     Monitor and controls the OS and HW
    3.1. Hypervisor Type 1:Bare metal virtualization
    3.2. Hypervisor Type 2:Hosted virtualization
    4. Protection Rings – Ring 0 - 3
    Hypervisor Type 1 and Type 2
    Hypervisor Type 1 or Bare metal virtualization
     SW directly installed on the HW
     No pre installed base OS
     Controls the HW and monitors the OS
     Fast because the VMs runs on the VMM
     Supports more VMs with no OS overhead
    Examples: VMware ESX and citrix Xen Server

    Hypervisor Type 2 or Hosted virtualization :


     OS pre-installed eg. Windows/Linux/MAC
     VMs installed like applications on Hypervisor
     VMs can use all HW resources of the host OS
     Host OS supplies all the device drivers
     Supports limited VMs with OS overhead
    Examples: VMware workstation and Microsoft Virtual PC
    Hypervisor Types
    Hypervisor Type 1 or Hypervisor Type 2 or
    Bare metal virtualization Hosted virtualization

    Source: www.vmware.com
    The Protection Rings
    • Rings typically from 0 – 3
    Protection Rings are the
    • Applications run in Ring 1 – 3 but typically in different Code execution
    Ring 3 levels in the CPU
    • Ring 0, highest privilege level, is where the
    OS normally runs

    • Codes executing in Ring 0 are in supervisor


    or kernel mode
    Ring -1
    • Hypervisor displaces the OS and runs in Ring
    0

    • Ring -1 is a new Ring level introduced by


    Intel and AMD in CPU, for HW assisted
    virtualization Source: wikipedia
    What is Virtualization ?

    • Virtualization is simply a technology that divides physical HW


    resources into separate virtual partitions called virtual machines.

    • Virtualization software program called Hypervisor is installed on


    the hardware to monitor and control the base Hardware and the
    Guest OS

    • Hypervisor, also called Virtual Machine Monitor, enables the


    multiple VMs (OSs) to share the resources of the single HW
    without conflict

    • Hypervisor Type 1 runs on Hardware and


    Hypervisor Type 2 runs on a Host OS
    Hardware architecture before and
    after Virtualization

    Source: wikipedia
    Major Types of virtualization
    1) Para virtualization
    2) Full virtualization -Non hardware assisted
    3) Full virtualization -Hardware assisted
    4) Full virtualization - Hosted virtualization
    5) Server virtualization
    6) Storage virtualization
    7) Network virtualization
    8) Applications virtualization
    9) Desktop virtualization
    Para Virtualization
    • Hypervisor SW layer on the HW and the VMs (OSs) are run the
    Hypervisor

    • Guest OSs are modified to run inside Hypervisors

    • VMM offers a special API that can only be used by modified OS to call
    the Hypervisor (Hypercalls)

    • The Hypervisor runs the Ring 0 CPU tasks


    (critical operations)on behalf of the multiple OS

    • Example: Microsoft Hyper-V and VMware ESX server


    Para Virtualization
    architecture and implementation
    Architecture Implementation

    Source: wordpress & techarena


    Full virtualization without HW support
    •Hypervisor layer on the HW and the VMs (OSs) run directly on the Hypervisor

    •The Hypervisor runs on Ring 0 and completely abstracts (decouples) the guest OS
    from the underlining HW

    •Guest OS kernels are not modified

    •Sensitive and privilege instructions (eg. accessing an I/O device) are trapped into
    the VMM and interpreted using Binary Translation

    •VMM provides all the services of the physical system in form of virtual BIOS, virtual
    memory and virtual devices

    •Examples: VMware ESX server and XEN Server


    Full Virtualization without HW support.

    Architecture Implementation

    Source: wordpress & techarena


    Full Virtualization with HW support
    Additional higher privilege Ring layer – Ring -1
    No Binary Translation of critical instructions

    Architecture Implementation

    Source: wordpress & techarena


    Intel-VT HW assist virtualization
    • Virtualization layer is in-built on the
    HW

    • Currently found in new generation


    Ring 3
    CPUs from Intel and AMD

    Ring 0 • common types are Intel-VT and AMD-


    V
    Ring -1

    Ring -1 • Provides extra protection layer (Ring -1)


    below Ring 0

    • Enables multiple VMs to run on one


    HW unmodified in Ring 0

    Source: wikipedia
    • No Binary Translation overhead
    Full virtualization - Hosted
    o A base OS like windows, Linux
    or MAC is pre – installed
    o The Hypervisor (VMM) runs
    on the OS
    o The VMs or guest OSs are
    then installed
    o Examples: VMware player,
    VMware workstation and
    Parallels Desktop for MAC
    o The VMM passes the I/O
    requests through the host OS
    o Host OS provides the device
    driver
    Source:vmware.com
    Virtualization case study
    Hosted Desktop virtualization

    • Hypervisor - VMware player

    • Used to host different OS

    • Used for testing SW

    • Used for Developing SW

    • Used for IT troubleshooting


    Source: chriswolf.com
    Disadvantages of Virtualization
    • Single point of failure if Host server fails

    • High demand on resources - sophisticated HW


    with increased RAM and CPU power

    • Performance problems cannot be detected in


    advance
    Advantages of Virtualisation

    • Management perspective

    • IT perspective

    • Business unit perspective


    Virtualisation - advantages
    Management perspective:

    • Maximum utilization of HW resources.

    • Reduced cost (TCO) – IT Budgets decrease in server, storage, power


    software and in testing and development.

    • Server operations and management becomes easier.

    • Business flexibility.

    • Real time response to dynamically changing computing needs.

    • Competitive edge in the market place


    Virtualisation - advantages
    IT perspective

    • Easy resources allocation and sharing

    • Server Consolidation and reduced number of


    physical servers

    • High Reliability and Availability

    • Better utilization of resources due to sharing.


    Virtualisation – advantages
    Business Unit Perspective

    • Application and database Queries run

    • Disaster recovery and Database Backup is faster

    • Improvement performance

    • Better reliability and stability due to built-in high availability functions.

    • Provide a safe and secure environment as per the Business Unit


    requirements.

    • Reduced Software licensing


    Conclusion

    • Virtualization enables multiple OSs to run on a


    single HW
    • Para Virtualization
    • Full virtualization with Hardware assist
    • Full virtualization without Hardware assist
    • Full virtualization with Hosted OS
    • Reduces IT budgets - CAPEX and OPEX
    A virtualisation case study

    • References :

    • Eric Siebert. VMware VI3 Implementation and Administration


    [Paperback] 1 edition (May 28, 2009)

    • White paper: Understanding Full Virtualization,


    Paravirtualization, and Hardware Assist

    • http://www.vmware.com/files/pdf/VMware_paravirtualization.pdf

    You might also like