02 Virtualization General - unimi.it · 2016-11-22 · –Xen ARM : Xen for mobile devices (led by Samsung) –PVOPS : Xen components and support in Linux Kernel (led by Oracle) •

VirtualizationIntroduction

Copyright©2015,Oracleand/oritsaffiliates.Allrightsreserved.|

SimonCOTERPrincipalProductManagerOracleVM&[email protected]://blogs.oracle.com/scoter

November21st,2016

Copyright©2015, Oracleand/oritsaffiliates.Allrightsreserved.|

SafeHarborStatementThefollowingisintendedtooutlineourgeneralproductdirection.Itisintendedforinformationpurposesonly,andmaynotbeincorporatedintoanycontract.Itisnotacommitmenttodeliveranymaterial,code,orfunctionality,andshouldnotberelieduponinmakingpurchasingdecisions.Thedevelopment,release,andtimingofanyfeaturesorfunctionalitydescribedforOracle’sproductsremainsatthesolediscretionofOracle.

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Whatisvirtualization?

OperatingSystem

App.A App.B App.C App.D

Hardware

VirtualizationLayer

VirtualContainer

App.A App.B

Hardware

VirtualContainer

App.C App.D

‘Nonvirtualized’ systemAsingleOScontrolsallhardwareplatformresources

VirtualizedsystemItmakesitpossibletorunmultipleVirtualContainersonasinglephysicalplatform

Virtualizationisabroadterm(virtualmemory,storage,network,etc)Virtualizationbasicallyallowsonecomputertodothejobofmultiplecomputers,bysharingtheresourcesofa

singlehardwareacrossmultipleenvironments


Howdiditstart?

• Servervirtualizationhasexistedforseveraldecades– IBMpioneeredmorethan30yearsagowiththecapability

to“multitask”• Theinceptionwasinspecialized,proprietary,high-endserverand

mainframesystems• By1980/90serversvirtualizationadoptioninitiatedareduction

– Inexpensivex86hardwareplatforms– Windows/LinuxadoptedasserverOSs


ComputingInfrastructure– 2000• 1machineà 1OSà severalapplications• Applicationscanaffecteachother• Bigdisadvantage:machineutilizationisverylow,mostofthetimesitisbelow

than25%

X86WindowsXP

X86Windows2003

X86Suse

X86RedHat

12%HardwareUtilization




App App App App App App App App


Virtualizationagain…

x86serverdeploymentsintroducednewITchallenges:• Lowserverinfrastructureutilization(10-18%)• Increasingphysicalinfrastructurecosts(facilities,power,cooling,etc)• IncreasingITmanagementcosts(configuration,deployment,updates,etc)• Insufficientfailoveranddisasterprotection

Thesolutionforalltheseproblemswastovirtualizex86platforms


ComputingInfrastructure- Virtualization• Itmatchesthebenefitsofhighhardwareutilizationwithrunningseveraloperatingsystems

(applications)inseparatedvirtualizedenvironments– Eachapplicationrunsinitsownoperatingsystem– Eachoperatingsystemdoesnotknowitissharingtheunderlyinghardwarewithothers

X86Multi-Core,MultiProcessor


X86WindowsXP

App.A

X86Windows2003

App.B

X86SuseLinux

App.C

X86RedHatLinux

App.D


EvolutionofSoftwaresolutions

• 1st Generation:Fullvirtualization(Binaryrewriting)– SoftwareBased– VMwareandMicrosoft

Time

• 3rd Generation:Silicon-based(Hardware-assisted)virtualization– Unmodifiedguest– VMwareandXenon

virtualization-awarehardwareplatforms

• 2nd Generation:Paravirtualization– Cooperativevirtualization– Modifiedguest– VMware,Xen

DynamicTranslation

VirtualMachine

Hardware

OperatingSystem

VirtualMachine…

Hypervisor

Hardware

VMVM

Hardware

VirtualMachine

VirtualMachine…

VirtualizationLogic

Hypervisor

…


FullVirtualization

• 1st Generationofferingofx86/x64servervirtualization• Dynamicbinarytranslation

– Theemulationlayertalkstoanoperatingsystemwhichtalkstothecomputerhardware

– TheguestOSdoesn'tseethatitisusedinanemulatedenvironment

• AllofthehardwareisemulatedincludingtheCPU• TwopopularopensourceemulatorsareQEMUandBochs

EmulatedHardware

VirtualMachine

GuestO

SDeviceDrivers

App.A

App.B

App.C

Hardware

HostOS

DeviceDrivers


FullVirtualization- Advantages

• Theemulationlayer– IsolatesVMsfromthehostOSandfromeachother– ControlsindividualVMaccesstosystemresources,preventinganunstableVMfromimpactingsystem

performance

• TotalVMportability– Byemulatingaconsistentsetofsystemhardware,VMshavetheabilitytotransparentlymovebetweenhosts

withdissimilarhardwarewithoutanyproblems• Itispossibletorunanoperatingsystemthatwasdevelopedforanotherarchitectureonyourownarchitecture

• AVMrunningonaDellservercanberelocatedtoaHewlett-Packardserver


FullVirtualization- Drawbacks• Hardwareemulationcomeswithaperformanceprice• Intraditionalx86architectures,OSkernelsexpecttorunprivilegedcodeinRing0

– However,becauseRing0iscontrolledbythehostOS,VMsareforcedtoexecuteatRing1/3,whichrequirestheVMMtotrapandemulateinstructions

• Duetotheseperformancelimitations,paravirtualization andhardware-assistedvirtualizationweredeveloped

Application Ring3

OperatingSystem

Ring0

Traditionalx86Architecture

Application Ring3

GuestOS Ring1/3

VirtualMachineMonitor

Ring0

FullVirtualization


Para-Virtualization

• TheGuestOSismodifiedandthusrunkernel-leveloperationsatRing1(or3)– theguestisfullyawareofhowtoprocessprivilegedinstructions– thus,privilegedinstructiontranslationbytheVMMisnolonger

necessary– TheguestoperatingsystemusesaspecializedAPItotalktothe

VMMand,inthisway,executetheprivilegedinstructions• TheVMMisresponsibleforhandlingthevirtualizationrequests

andputtingthemtothehardware

VirtualMachineMonitor

VirtualMachine

GuestO

S

DeviceDrivers

App.A

App.B

App.C

SpecializedAPI

Hardware

Hypervisor

DeviceDrivers


Para-Virtualization• Today,VMguestoperatingsystemsareparavirtualized usingtwodifferentapproaches:

– RecompilingtheOSkernel• Paravirtualization driversandAPIsmustresideintheguestoperatingsystemkernel• YoudoneedamodifiedoperatingsystemthatincludesthisspecificAPI,requiringacompilingoperatingsystems

tobevirtualizationaware– Somevendors(suchasNovell)haveembracedparavirtualization andhaveprovidedparavirtualized OS

builds,whileothervendors(suchasMicrosoft)havenot– Installingparavirtualized drivers

• Insomeoperatingsystemsitisnotpossibletousecompleteparavirtualization,asitrequiresaspecializedversionoftheoperatingsystem

• Toensuregoodperformanceinsuchenvironments,paravirtualization canbeappliedforindividualdevices• Forexample,theinstructionsgeneratedbynetworkboardsorgraphicalinterfacecardscanbemodifiedbefore

theyleavethevirtualizedmachinebyusingparavirtualized drivers


Hardware-assistedvirtualization

• TheguestOSrunsatring0• TheVMMusesprocessorextensions(suchasIntel®-VTorAMD-V)to

interceptandemulateprivilegedoperationsintheguest• Hardware-assistedvirtualizationremovesmanyoftheproblemsthat

makewritingaVMMachallenge• TheVMMrunsinamoreprivilegedringthan0,avirtual-1ringis

createdVirtualMachineMonitor

VirtualMachine

GuestO

SDeviceDrivers

App.A

App.B

App.C

SpecializedAPI

Hardware

Hypervisor

DeviceDrivers


Hardware-assistedvirtualization

• Pros– ItallowstorununmodifiedOss(solegacyOScanberunwithoutproblems)

• Cons– SpeedandFlexibility

• AnunmodifiedOSdoesnotknowitisrunninginavirtualizedenvironmentandso,itcan’ttakeadvantageofanyofthevirtualizationfeatures– Itcanberesolvedusingparavirtualization partially


ABriefHistoryofXenintheCloud

Oct‘03

XenPresentedatSOSP

XCP1.xCloudMgmt

‘08‘06

AmazonEC2andSlicehostlaunched

RackspaceCloud

Late 90s

XenoServer Project(CambridgeUniv.)

‘09 ‘11

XCPAnnounced

‘12

XCPpackagesinLinux

XenforARMbasedServersPVHmode

Linux3.0


• GuardianofXenHypervisorandrelatedOSSProjects• XenGovernancesimilartoLinuxKernel• Projects– XenHypervisor(ledby5committers,2fromCitrix)– XenCloudPlatformakaXCP(ledbyCitrix)– XenARM:Xenformobiledevices(ledbySamsung)– PVOPS:XencomponentsandsupportinLinuxKernel(ledbyOracle)

• 10+vendorscontributingmorethan1%totheproject(AWS,AMD,Citrix,GridCentric,Fujitsu,Huawei,iWeb,Intel,NSA,Oracle,Samsung,Suse,…)

Xen.org

Copyright©2015, Oracleand/oritsaffiliates.Allrightsreserved.| 18

XenVariantsforServer&Cloud

XenHypervisor XCP

Increasedleveloffunctionalityandintegrationwithothercomponents

Default/XL(XM)Toolstack /Console Libvirt /VIRSH XAPI /XE

Products OracleVM HuaweiUVP CitrixXenServer

GetBinaries from… LinuxDistros LinuxDistros Debian &Ubuntu

ISO fromXen.org

Usedby… ManyOthers


Extendingtheconceptofvirtualizationfordesktops• Servers

– Hostedvirtualization- mainframes– VMMs/BareMetalhypervisors– OSvirtualization

• Desktops– Desktopvirtualization– Server-sideworkspacevirtualization– Client-sideworkspacevirtualization

• Applicationvirtualization– Applicationisolation– Applicationstreaming


DesktopVirtualization• AVMMorhypervisorrunningonaphysicaldesktop

• Examplesinclude:– MicrosoftVirtualPC– OracleVMVirtualBox

– ParallelsDesktopforMac

– VMwareFusion

• Usecasesinclude:– EmulatingWindowsgamesontheMacintosh

– TestingcodeinsideVMs– Underpinningclient-sideworkspacevirtualization

• DesktophypervisorsandVMMsdon’tnecessarilyscaletomeetenterpriseneeds;that’swhymostoftheprovidershaveserverproductsaswell


Server-sideworkspacevirtualization• Aworkspace(desktopoperatingsystemwithcustomconfiguration)runninginsideavirtualmachine

hostedonaserver

• Examplesinclude:– VMwareVDI

• Usecasesinclude:– Centrallymanageddesktopinfrastructure

– Securityenforcementandlockdown

• Apoolofvirtualworkspacesresidesontheserver.RemoteuserslogintothemfromanynetworkeddeviceviaMicrosoft’sRemoteDesktopProtocol(RDP)

• Userscancustomizetheirvirtualworkspacetotheirheart’scontent,whileoperatorsenjoytherelativelystraightforwardtaskofmanagingdesktopconfigurationononecentralserver

• Connectionbrokersarbitratebetweenapoolofvirtualworkspacesresidingonacentralserver

• Thebiggestproblemwithserver-hostedworkspacevirtualizationisthatit’sabandwidthhog.Performanceisconstrainedbytheperformanceofyournetwork


Blade&Servers

• Manually installed servers, manually configured networks, manually configured operating systems, lightly automated deployments


VirtualMachines

• Software installed servers (guests), partially automated networks, manually configured operating systems, lightly automated deployments


Containers:LXC&Docker• Software installed servers (guests),

fully automated network setup, automated OS setup, automated application setup, automated deployments, slice up VM into smaller units• Each unit appears to the application

as owning it’s own OS• In reality, all units share the same

kernel


DevOps

• DevOps ("development" and "operations") aims at establishing a culture and environment where building, testing, and releasing software, can happen rapidly, frequently, and more reliably.


Vision:Virtualization&Container…….together

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Q&A

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Documents

02 Virtualization General - unimi.it · 2016-11-22 · –Xen ARM : Xen for mobile devices (led by Samsung) –PVOPS : Xen components and support in Linux Kernel (led by Oracle) •