parth virt

Virtualization

Parth Monga<[email protected]>

July 3rd, 2014

Outline

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Introduction & History

Basic Principles & Concepts

Types of Virtualization

Types of Hypervisor

Use Cases

Survey Results

Virtualization:Intro

• Proven software technology rapidly transforming IT Landscape.

• Fundamentally changing the way that people compute.

• Breaks the bond of traditional hardware computing systems.

• Revolutionizing the whole IT infrastructure ecosystem by transforming

Hardware into Software.

“Virtualization means to create a virtual version of a device or resource, such as

a server, storage device, network or even an operating system where the

framework divides the resource into one or more execution environments.

Devices, applications, human users are able to interact with the virtual

resources as if it were a real single logical resource.”

Virtualization:History

• Traces root back to 1960’s when Mainframe was King.

• Mainframe:Inflexible/Only one user at a time can feed mainframe a program.

• Tasks was batched into there own workloads.

• First Customer’s of Virtualization: THE BIRTH OF VIRTUALIZATION

• MIT: Project MAC(Mathematics and computation) later renamed to

Multiple Access Computer. $2 Million Grant:DARPA to fund research

specifically in areas of os, ai and computational theory.

• Bell LABS: Needed a Time Sharing System.

• IBM designed CP-40 main frame.Only used in Labs not for commercial.

• CP-67 evolved as the first commercial mainframe to support virtualization.

• S/360-67 CP/CMS first stable release in 1972

• CP-Control Program & CMS-Console Monitor System

IBM System360

Current x86

In essence, virtualization lets you transform hardware into software. Use software such as VMware ESX Server to transform or “virtualize” the hardware resources of an x86-based computer—including the CPU, RAM, hard disk and network controller—to create a fully functional virtual machine that can run its own operating system and applications just like a “real” computer.


• Virtualization allows a single physical server to simultaneously run multiple VMs.• Each virtual machine is self-contained & protected from other VMs on the same server.• Virtual machine appear to be real machines from outside world.

The Role of an OS

Program A

OperatingSystemScheduler

MemoryProgram B

Program C

Abstract from the Hardware !

CPU1CPU2


Same role than an OSBUT !

Virtualization has something more !

Principles:Memory Isolation from 'Outside'

Provides (Virtual) Access to Hardware

Can Handles Multiple Instances

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Main Keywords

Hypervisor (aka Virtual Machine Manager):Program providing the virtualization platform.

Host OS (aka Supervisor):Operating System on which is executed the Hypervisor.

Guest OS:Operating System executed inside the Hypervisor.

Virtual Machine (VM):Instance of one environment provided by the Hypervisor.

Server Virtualization

Consolidating multiple physical servers into virtual servers that run on a single physical

server.

OS Virtualization

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A type of server virtualization technology which works at the OS layer. The physical server and single instance of the operating system is virtualized into multiple isolated partitions, where each partition replicates a real server. The OS kernel will run a single operating system and provide that operating system functionality to each of the partitions. Pro’s

• Least Overhead.• Highest Performance• Highest Density

Con’s• Supports only one os as base and

guest os• All os in the container should have

same version and same patch level of the base os.

• Base os crash, guest becomes unavailable.

• Examples: OpenVZ, Virtuozzo

Hardware Emulation

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In hardware emulation, a specialized software, which is also known as hypervisor, creates hardware emulation for OS in a single server. They can host different types of OS in a single server. The OS loaded into each virtual machine works as a standalone and unmodified OS. When a VM (virtual machine) is running, the hypervisor make changes to the part of the OS that make system calls. Hypervisor changes the OS by entering a piece of code—which is known as binary translation- to the OS when it is running. Binary translation takes place in four parts of the OS ( memory, processor, network, storage) that interact with the hardware.

Pros’s• You do not have to modify the OS and applications to run on the virtual

environment.• Example: VMware

Hypervisor

A hypervisor is a hardware virtualization technique that allows multiple guest operating systems (OS) to run on a single host system at the same time. The guest OS shares the hardware of the host computer, such that each OS appears to have its own processor, memory and other hardware resources.• A hypervisor is also known as a virtual machine manager (VMM).• Term Coined by IBM.

Type 1 Hypervisor

Type 1 hypervisor is also known as bare-metal implementation because they sit directly on the top of hardware, without needing any operating system. Since they can directly communicate with hardware resources, they are much faster than type 2 hypervisor.

Pro’s• Single virtual machine crash does not

affect rest of guest system.• More Secure than type2.• Generate less overhead and fast.• Example:Vmware Esx, Microsoft Hyper-V

Type 2 Hypervisor

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Type 2 hypervisor resides on top of the operating system. Since they cannot directly communicate with the hardware, they are less efficient than the type 1.

Pro’s• Install is easier.• OS takes care of all the hardware,

that’s why can support wide range of hardware.

Con’s• More points of failure, anything that

affects the stability of base os can also affect the guest os.

Example: Vmware Player and Workstation

Paravirtualization

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Paravirtualization does not emulate hardware environment in software, instead it coordinates or multiplexes access to hardware resources in favor of virtual machine.In paravirtualized environment, a guest OS( called DomainU) is directly installed on the hypervisor(bare-metal architecture) that does not contain any device drivers for network and storage. Instead a privileged guest OS-also known as DomainO-has direct access to hardware. All guest OSes access hardware resources via DomainO). When a guest OS(virtual machine) needs to access hardware resources it sends a message to DomianO that access the hardware on behalf of guest OS. When data returns to the hardware, DomainO reads the information and passes it back to the guest operating system that has request it.DomainO is a standard OS such as Linux that has been modified to communicate with hypervisor to control access to hardware.Example: XEN

Application VirtualizationApplication virtualization is relatively simple in that an application runs on your desktop without ever having installed it. However, unlike using Terminal Services, the virtualized application executes locally, using local resources (e.g., processor, memory, disk, and network card). In other words, the application runs, saves data, prints, and acts as if it’s installed locally even though it is not. On top of this, you can run multiple versions of the same application on your desktop without conflict, and run conflicting applications like different versions of Access or Outlook with out conflict—again, with all the applications executing locally – and not as “screen scrapes” from a remote Terminal Server.AppV is best utilized if the clients machines are more powerful and you do not need very powerful server.

PresentationVirtualization

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The term "Presentation Virtualization" is used to cover technologies like Microsoft Terminal Server or Citrix MetaFrame/Presentation Server/XenApp. Also, any Remote Desktop Connection (like RDP to remote PCs, VNC..) are considered as Presentation Virtualization. From the Client's perspective, in Presentation Virtualization the application runs on a remote computer (literally consumes RAM and CPU resources there) but the User Interface (Windows output, Mouse+Keyboard input) are transmitted over the network to the Client (on the Client the is only the "Presentation layer" of an application).

Presentation Server is best if you are using thin clients and wants to use everything on the server

Network Virtualization

With network virtualization, the network is “carved up” and can be used for multiple purposes such as running a protocol analyzer inside an Ethernet switch. Components of a virtual network could include NICs, switches, VLANs, network storage devices, virtual network containers, and network media.

Storage Virtualization

With storage virtualization, the disk/data storage for your data is consolidated to and managed by a virtual storage system. The servers connected to the storage system aren’t aware of where the data really is. Storage virtualization is sometimes described as “abstracting the logical storage from the physical storage.

Virtualization Real-World Use Cases

VirtualizationSoftwares & HardwaresAMD-V OpenVZ (OS-level virtualization)

Qemu (emulation)

User-Mode Linux(paravirtualization)

VirtualBox(full-virtualization, hardware virtualization)

VMWare(full-virtualization, hardware virtualization)

Xen (paravirtualization)

(hardware virtualization)

chroot (OS-level virtualization)

Bochs (emulation)

BSD Jail(OS-level virtualization)

Intel-VT(hardware virtualization)

Linux KVM(hardware virtualization)

Linux VServer(OS-level virtualization)

Virtualization Survey 2013 Q3

• VMware continues to dominate the virtualization space with over 54% market share.• More than 75% of their entire IT infrastructure is now virtualized.• 12% of those surveyed admitted to using Xen and KVM, leading open source virtualization

platforms.• 52% of respondents indicated that their preferred private cloud supplier was VMware.

Virtualization Survey 2013 Q3

Questions ?

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