1、雲端運算虛擬主機技術的發展Overview雲端運算概念虛擬機的概念桌面虛擬化產品與伺服器虛擬化產品雲端運算與虛擬機雲端計算下的虛擬機管理機制目前的困難與處理方式可能的研究主題雲端運算概念雲端是什麼意思？資訊人員在畫網路圖，若需要在圖上畫網際網路時，習慣畫一朵雲來代表成千上萬的電腦網路。雲端運算概念(續)例如要表達：公司內有一台電腦A要傳送資料到另一間公司的電腦B電腦A電腦B公司A公司BInternet網路上成千上萬的電腦連線雲端運算概念(續)公司A公司BInternet網路上成千上萬的電腦連線電腦A電腦B這時我們會畫一朵雲去做簡化、來代表這錯綜複雜、無邊無際的Internet雲端運算概念(續)
2、當電腦連上了網際網路、通往外面的世界時，也就代表電腦連上了”雲”。網際網路雲端運算概念(續)因此“雲”有“網際網路上的電腦”的意思。雲端運算概念(續)雲端運算要使用網際網路上另一端的電腦幫我們處理事情雲端運算概念(續)雲端運算可以使用網路另一端運算能力強大的電腦幫你處理事情，讓運算能力不佳的裝置，如手機，也使用只有高速電腦才能執行的功能。雲端運算概念(續)雲端不只是只有網路而已雲端技術還包含了儲存設備、虛擬化技術、網路服務等等技術知名分析公司Gartner認為，目前對雲端計算的定義，涵蓋太多雜七雜八的技術，應該用二分法來區別：雲端服務(Cloud Computing Services)雲端技術
3、(Cloud Computing Technologies)雲端的商機雲端的服務需由服務商持續提供，很適合使用持續性收費，而非賣斷式的收費。類似水、電費、手機通信費的收費模式，可得到較長久穩定的收益。可依服務使用的質與量來實行不同等級的收費，如可依服務的功能多寡、使用容量大小來定價。Lets back to the realityA Lot of Servers/Machines.Web serverMail serverDatabase serverFile serverProxy serverApplication serverand many othersA Lot of Servers
4、/Machines. The data-centre is FULL Full of under utilized serversComplicate in management Power consumption Greater wattage per unit area than everElectricity overloadedCooling at capacityEnvironmental problemGreen ITVirtualizationVirtualization - the abstraction of computer resources. Virtualizatio
5、n hides the physical characteristics of computing resources from their users, be they applications, or end users.This includes making a single physical resource (such as a server, an operating system, an application, or storage device) appear to function as multiple virtual resources; it can also in
6、clude making multiple physical resources (such as storage devices or servers) appear as a single virtual resource.HardwareOperatingSystemApplicationsHardwareOperatingSystemApplicationsHypervisorVirtualization - a Server for Multiple Applications/OSHardwareOperatingSystemApplicationsHardwareOperating
7、SystemApplicationHypervisorOperatingSystemApplicationOperatingSystemApplicationOperatingSystemApplicationOperatingSystemApplicationsHypervisor is a software program that manages multiple operating systems (or multiple instances of the same operating system) on a single computer system. The hyperviso
8、r manages the systems processor, memory, and other resources to allocate what each operating system requires. Hypervisors are designed for a particular processor architecture and may also be called virtualization managers.Capacity UtilizationStand alone system (low)Virtualized system (high)Low utili
9、zedHigh utilized* But not overloaded現在的電腦效能相當強大，但卻有非常多的電腦平常只有使用不到20%的運算資源，甚至更少。但因為種種需求，又無法降低電腦數量，因此把數台電腦“虛擬化”塞進一台功能較強大的實體主機，榨乾實體主機的運算資源，成了一種受歡迎的方法。虛擬機的概念(續)虛擬機可允許一台實體主機同時執行多個作業系統。一台強大電腦主機能做30台電腦的事，在佔用面積、耗電量、空調、維護人事成本上，都能有效節約。可在一台實體主機內執行多個虛擬主機，每一台虛擬主機既可以互相用線路連線、又可以獨立運作，互不干涉。可將多台實體主機合併成一台大的資源池(Resourc
10、e Pool)，統籌管理、分配在上面的虛擬機。虛擬機的概念(續)只要實體主機的硬體能力許可，便能靈活地建立或移除多台虛擬機，可保持高度彈性。虛擬主機往往在映像檔內直接執行、存取的檔案、作業系統，使得備份、搬移虛擬機較實體主機容易許多。虛擬化可使實體主機擴增、維修、更換不須關閉虛擬機，只要把裡面的虛擬機搬移到別的虛擬機即可。可使用虛擬機測試不穩定的軟體，再利用快照完全還原整個系統(僅需數秒鐘)，而不須在實體主機測試。虛擬機的概念(續)Host Operation System (Host OS)：用來執行虛擬機軟體的OSGuest Operation System (Guest OS)在虛擬機器
11、上執行的OS例如：在Windows XP上安裝VirtualBox，並在VirtualBox內安裝Ubuntu，這時的XP就是Host OS，而Ubuntu就是Guest OSWhy now?19601999IBM, CP-40, CP/CMS, S/360-370, VM370, Virtual PC, VMware20002005IBM z/VM, Xen2006Intel VT-xAMDs AMD-V 2008Hardware evolution Faster CPU clock than everThough almost hit its topMore CPU cores in a
12、single chip 4-core CPUs already in the market6- or 8-core CPUs will be there soonMulti-core architectures make parallel processing more realizable Virtualization support on chip from CPU manufacturers (e.g., Intel, AMD)Software maturityMore than one credible player in the marketAvailable and stable
13、open-sourced softwareOS, DB, Web server, Java, PHP, gcc, etc.Established and mature software standardsWeb service, XML, SOAP, COM, etc.Types of VirtualizationVirtual memoryDesktop virtualizationPlatform virtualizationFull virtualizationParavirtualization Hardware-assisted virtualizationPartial virtu
14、alizationOS-level virtualizationHosted environment (e.g. User-mode Linux)Storage virtualizationNetwork virtualizationApplication virtualizationPortable applicationCross-platform virtualizationEmulation or simulationHosted Virtual DesktopIn this talk, we mainly focus on Platform virtualization which
15、is mostly related to cloud-computingFull virtualizationBinary transaltionHardware-assisted virtualizationParavirtualizationOS-level virtualizationHosted environment (e.g. User-mode Linux)Hardware levelOperating system levelApplication levelCategory in Wiki虛擬機的概念(續)半虛擬化與全虛擬化半虛擬化因直接使用硬體資源，效率遠遠高於全虛擬化彈性
16、較低，Guest OS核心需經過修改才能運作因為半虛擬化直接使用硬體資源，所以虛擬機必須和實體主機使用同一版本的核心全虛擬化全虛擬化所使用的硬體是虛擬出來，因此虛擬機較容易在不同硬體的實體主機之間搬移但因為硬體是虛擬，效能較半虛擬化低OS不受實體主機限制，可安裝多種不同的OS虛擬機的目前發展桌面虛擬化產品與伺服器虛擬化產品桌面虛擬化產品：安裝在各作業系統上，如Windows XP、CentOS內執行虛擬機，可用於測試、生產和開發例：XenVMware Workstation桌面虛擬化產品與伺服器虛擬化產品(續)伺服器虛擬化產品：產品整合一個精簡專用的作業系統，不須另行安裝作業系統；因作業系統無
17、額外功能服務，可獲得較好的效能，但也無法在本機管理，須由另一台Client電腦連線管理，適合用於多台伺服器整合例：XenServerVMware ESXi ServerXenXen是一個開放原始碼的虛擬主機技術。最早是由XenSource的創辦人於劍橋大學時所開發，目前XenSource則被Citrix所併購。以高效能的半虛擬化著稱產品：XenXenServerVMwareVMware公司銷售的商業軟體產品之一允許多個x86虛擬機同時被創建和運行可執行Windows、Linux、BSD有推出其它產品輔助虛擬機的管理和移植產品：VMware WorkstationVMware ESXi Serv
18、er虛擬機的DEMO (在Solaris上同時執行Windows XP)Using VMRAMOS and User files (HD)FileInstallation CD/DVDISO imagesVM duplicationChallengeCopyright authorizationRe-configurability of VM imagesManagement of VM imagesBilling SecurityMigration ChallengeLive migration (without stopping the VM)How to ?The users have
19、no patienceSpeedHow to copy a 120GB image file in a second?Intelligent migration Load balance problemSecurityDistributionLinux 1/2Linux 2/2WinXP 2/2WinXP 2/2Solaris 1/1ChallengeDistributed OSRe-write OSProbably via MPI-like technologyLive and smart distribution Security虛擬機使用例子使用1台伺服器加上50組螢幕鍵盤滑鼠，建構一間
20、50人用的電腦教室。每位使用者使用一組螢幕鍵盤滑鼠，連線到伺服器上各自的虛擬機。資料可集中管理，還原、複製便利，且無學生主機汰舊換新的問題。可能應用到企業組織中，使得組織內個人電腦管理變得更方便。虛擬機使用例子(圖例)無主機、只有螢幕鍵盤滑鼠和一個專用控制器伺服器(內有許多虛擬主機)WinXP with AutoCADWinXP with MatLabLinux with Solaris with Solution provider: 大同世界科技雲端運算與虛擬機易於分配、量化實體主機的運算資源，以便管理維護及定價收費。例：把電腦的資料量化，就可採用類似每一度的電，就收費三塊錢的方式可依虛擬主
21、機被分配到的儲存容量、CPU顆數、記憶體大小來實行差別定價可彈性維護虛擬主機，輕易地將虛擬機從一台實體機搬移到另一台雲端計算下的虛擬機管理機制虛擬機架構的軟體雖具有基本的管理方式，但是雲端計算之中所使用的數量會遠大於虛擬機軟體所能提供，因此需要特別去考慮虛擬機管理機制。需考慮的管理機制虛擬機器的管理資料儲存的管理工 作負載管理BenefitsMaximizing computing resourcesSimulation and testingOSAPPNetworkingEtc.DisadvantagesSecurityHardware/software supportsCostEtc. I
22、ssues in Virtualization for Cloud-ComputingAspects and expectation from End-userOperator/ManagerVirtualizationIssues in Virtualization for Cloud-ComputingVirtualization implemented on a single machine (with multi-core CPUs) a cluster of machines (with multi-core CPUs) The state-of-the-artRunning a X
23、en or a cluster of XensHardwareOperatingSystemApplicationHypervisorOperatingSystemApplicationOperatingSystemApplicationOperatingSystemApplicationOperatingSystemApplicationsHardwareOperatingSystemApplicationHypervisorOperatingSystemApplicationOperatingSystemApplicationOperatingSystemApplicationHardwa
24、reHardwareOperatingSystemApplicationOperatingSystemApplicationOperatingSystemApplicationOperatingSystemApplicationOperatingSystemApplicationsVirtualizationoror?ManagementSystem Issues in Virtualization for Cloud-ComputingAbiquo/abicloud may provide partial solutionsHardwareOperatingSystemApplication
25、HypervisorOperatingSystemApplicationOperatingSystemApplicationOperatingSystemApplicationOperatingSystemApplicationsHardwareOperatingSystemApplicationHypervisorOperatingSystemApplicationOperatingSystemApplicationOperatingSystemApplicationOperatingSystemApplicationsHardwareOperatingSystemApplicationHy
26、pervisorOperatingSystemApplicationOperatingSystemApplicationOperatingSystemApplicationOperatingSystemApplicationsHardwareOperatingSystemApplicationHypervisorOperatingSystemApplicationOperatingSystemApplicationOperatingSystemApplicationOperatingSystemApplicationsVirtualizationIssues in Virtualization for Cloud-ComputingThe virtualization of special hardwareE.g., GPUWhat happensA program which takes 10-hour of running time on a single CPU This program is installed in a virtual machine with 18 cores?This program is installed in two virtual machines?
