1.Introduction to virtualization
Download as PPTX, PDF12 likes13,128 views
This document provides an introduction to virtualization including: 1) The benefits of virtualization like efficient resource utilization and strong isolation between virtual machines. 2) A brief history of virtualization from the 1960s mainframe era to modern ubiquitous cloud computing. 3) Popular use cases of virtualization including cloud computing, virtual desktop infrastructure, and mobile virtualization. 4) Basic terminologies that distinguish type-1 and type-2 virtual machine monitors as well as full and para-virtualization methods.
![History - Reborn (2/4)
• The late 1990s
• Regain attention for “server consolidation”
• Toward cost-effective large-scale computing
• Stanford’s research project: Disco
• They founded VMware in 1998
Disco: Running Commodity Operating Systems on Scalable Multiprocessors [SOSP’97]
6/30](https://image.slidesharecdn.com/1-150328170334-conversion-gate01/85/1-Introduction-to-virtualization-6-320.jpg)
![History - Renaissance (3/4)
• 1998-2002
• VMware
• “Full-virtualization”
• Running unmodified OS
• Starting with SW-based binary translation
• Success in industry and academia
• VMware‘s state-of-the-art techniques in SOSP and OSDI
• 2003
• Xen
• University of Cambridge’s project: Open source!!!
• “Xen and Art of Virtualization” [SOSP’03]
• “Para-virtualization”
• Modified OS for near-native performance: Linux on x86
• 2003-
• Virtualization research renaissance based on Xen
• 2007: Acquired by Citrix
7/30](https://image.slidesharecdn.com/1-150328170334-conversion-gate01/85/1-Introduction-to-virtualization-7-320.jpg)
![Why Virtualization? (1/6)
• Efficient resource utilization
• Low resource utilization of each server machine
• Low total cost of ownership (TCO)
• Low cost of infrastructure and energy
VM
VM
VM
VMM
CPU
CPU
CPU
CPU
The Case for Energy-Proportional Computing [IEEE Computer’07]
Average CPU utilization of 5000+ Google’s servers
Mostly 0-50% utilization
9/30](https://image.slidesharecdn.com/1-150328170334-conversion-gate01/85/1-Introduction-to-virtualization-9-320.jpg)
![Why Virtualization? (4/6)
• Strong isolation
• Strong isolation between co-located VMs
• Fault containment or isolation
• Safe from bugs and malicious attacks
VMM
VM
Hardware
VM
Safe
OS OS
An empirical study of operating systems errors [SOSP’01]
Hardware
App
OS
App
VMM is much smaller than OS
Low trusted computing base (TCB)
OSes, especially drivers, are error-prone
12/30](https://image.slidesharecdn.com/1-150328170334-conversion-gate01/85/1-Introduction-to-virtualization-12-320.jpg)
![Why Virtualization? (5/6)
• Multiple OSes on a single device
• OS dependency of legacy SW
• Linux + Windows, Android + iOS
• Different requirements of SW
• Virtualization for embedded or mobile systems
• RTOS + GPOS
• Building secure systems
• Security-enhanced OS + GPOS
Allowing for GPOS and RTOS:
The unique virtualization
needs of mission-critical
embedded systems,
TenASysTerra: A Virtual Machine-Based Platform for Trusted Computing [SOSP’03]
Trusted VMM
13/30](https://image.slidesharecdn.com/1-150328170334-conversion-gate01/85/1-Introduction-to-virtualization-13-320.jpg)
![Mobile Virtualization
• Academia
• Columbia university’s projects
• Cells [SOSP’11]
• KVM for ARM [OLS’10]
• Cortex-A8, A9
• Now running on A15
Cells: A Virtual Mobile Smartphone Architecture [SOSP’11]
Linaro Ubuntu 11.04 for ARM
running in VM by KVM/ARM
(Cortex-A15 in Fast Model 6.1)
OS-level virtualization
24/30](https://image.slidesharecdn.com/1-150328170334-conversion-gate01/85/1-Introduction-to-virtualization-24-320.jpg)
1.Introduction to virtualization
- 2. Outline • Goals • Understanding the benefits of virtualization in IT industry and how to virtualize HW resources • Schedule • Introduction to virtualization • OS vs. VMM • CPU virtualization and scheduling • Memory virtualization and management • I/O virtualization • Live VM migration • Introduction to Systemtap 2/30
- 3. How to Learn Virtualization? • Conference proceedings • SOSP • Symposium on Operating Systems Principles • OSDI • Symposium on Operating Systems Design and Implementation • ASPLOS • International Conference on Architectural Support for Programming Languages and Operating Systems • USENIX ATC • USENIX Annual Technical Conference • EUROSYS • European Conference on Computer Systems • VEE • International Conference on Virtual Execution Environments • SOCC • ACM Symposium on Cloud Computing • Open source software • Xen, KVM, VirtualBox 3/30
- 4. What is Virtualization? • Multiple OSes on a single machine • Giving an illusion that each OS is running on real HW • Virtual Machine Monitor (VMM) • Another layer of kernel to virtualize multiple OSes • Also called “hypervisor” • An OS as a supervisor is no more HW-dictator! Hardware Virtual Machine Monitor Windows App App App Linux App App App Mac App App 4/30
- 5. History – Born and Died (1/4) • 1960s-1970s • High cost of computing machines • IBM VM/370: A VMM for IBM mainframe • 1980s-1990s • But, lost attentions since PC era (1980s) • Cheap HW No need to share hardware • CPU did not support virtualization well • High engineering cost and overhead Powerful & expensive hardware 5/30
- 6. History - Reborn (2/4) • The late 1990s • Regain attention for “server consolidation” • Toward cost-effective large-scale computing • Stanford’s research project: Disco • They founded VMware in 1998 Disco: Running Commodity Operating Systems on Scalable Multiprocessors [SOSP’97] 6/30
- 7. History - Renaissance (3/4) • 1998-2002 • VMware • “Full-virtualization” • Running unmodified OS • Starting with SW-based binary translation • Success in industry and academia • VMware‘s state-of-the-art techniques in SOSP and OSDI • 2003 • Xen • University of Cambridge’s project: Open source!!! • “Xen and Art of Virtualization” [SOSP’03] • “Para-virtualization” • Modified OS for near-native performance: Linux on x86 • 2003- • Virtualization research renaissance based on Xen • 2007: Acquired by Citrix 7/30
- 8. History - Ubiquitous (4/4) • 2005-2006 • HW-assisted virtualization • x86 virtualization • Intel VT-x & AMD-V • Running unmodified OS with near-native performance • Default functionality now • 2006-now • Cloud computing • Infrastructure-as-a-Service (IaaS) • Virtual desktop infrastructure (VDI) • Mobile virtualization • ARM virtualization technology (Cortex-A15) 8/30
- 9. Why Virtualization? (1/6) • Efficient resource utilization • Low resource utilization of each server machine • Low total cost of ownership (TCO) • Low cost of infrastructure and energy VM VM VM VMM CPU CPU CPU CPU The Case for Energy-Proportional Computing [IEEE Computer’07] Average CPU utilization of 5000+ Google’s servers Mostly 0-50% utilization 9/30
- 10. Why Virtualization? (2/6) • Flexible VM relocation • “Live VM migration” • Flexible VM relocation with near-zero downtime • Flexible load balancing • Relieving resource bottleneck VM VM VM CPU CPU CPU CPU 10/30
- 11. Why Virtualization? (3/6) • Flexible VM relocation • “Live VM migration” • Flexible VM relocation with near-zero downtime • High availability VM SW or HW maintenance (upgrade or fix) 11/30
- 12. Why Virtualization? (4/6) • Strong isolation • Strong isolation between co-located VMs • Fault containment or isolation • Safe from bugs and malicious attacks VMM VM Hardware VM Safe OS OS An empirical study of operating systems errors [SOSP’01] Hardware App OS App VMM is much smaller than OS Low trusted computing base (TCB) OSes, especially drivers, are error-prone 12/30
- 13. Why Virtualization? (5/6) • Multiple OSes on a single device • OS dependency of legacy SW • Linux + Windows, Android + iOS • Different requirements of SW • Virtualization for embedded or mobile systems • RTOS + GPOS • Building secure systems • Security-enhanced OS + GPOS Allowing for GPOS and RTOS: The unique virtualization needs of mission-critical embedded systems, TenASysTerra: A Virtual Machine-Based Platform for Trusted Computing [SOSP’03] Trusted VMM 13/30
- 14. Why Virtualization? (6/6) • Other benefits • Strong security monitoring • Security monitoring outside OSes • Ease of deployment • Virtual appliance • A bundle of OS and applications • Flexible testing and debugging • Building distributed environments on a single machine • Kernel development and debugging • VM-based recording and replaying 14/30
- 15. Use Cases • Cloud computing • Virtual desktop infrastructure • Mobile virtualization 15/30
- 16. Virtualization & Cloud Computing • Virtualized data centers Virtualization 1.x: Near term Virtualization 2.0: Emerging Virtualization 3.0: Future Virtualization 3.0 The fully virtualized datacenter for cloud services 2013+ Virtualization 1.x Virtualization 2.0 2009 출처: IDC 2010 report 16/30
- 17. Virtualization & Cloud Computing • VM-based resource pool for various demands • Infrastructure-as-a-Service (IaaS) 17/30
- 18. Virtualization & Cloud Computing • Many providers use commercial & open-source VMMs Virtualization Solutions Cloud Providers 18/30
- 19. Virtual Desktop Infrastructure (VDI) • Desktop provisioning Dedicated workstations VM VM VM VM VM - Energy wastage by idle desktops - Resource underutilization - High management cost - High maintenance cost - Low level of security + Energy savings by consolidation + High resource utilization + Low management cost (flexible HW/SW provisioning) + Low maintenance cost (dynamic HW/SW upgrade) + High level of security (centralized data containment) VM-based shared environments 19/30
- 20. Virtual Desktop Infrastructure (VDI) • VDI is also hot in Korea 20/30
- 21. Virtual Desktop Infrastructure (VDI) • VMware VDI • Pioneer of VDI 21/30
- 22. Mobile Virtualization • Trends of consumer electronics • Digital convergence • What do consumer electronics(CE) devices want to achieve? Reliability Trustworthiness for primary functions Extensibility Flexibility for adding features as needed Business Phone Personal Phone 22/30
- 23. Mobile Virtualization • BYOD: Bring Your Own Device • Consolidating business and personal computing environments on a single device Business VM Personal VM Hypervisor Managed domain 23/30
- 24. Mobile Virtualization • Academia • Columbia university’s projects • Cells [SOSP’11] • KVM for ARM [OLS’10] • Cortex-A8, A9 • Now running on A15 Cells: A Virtual Mobile Smartphone Architecture [SOSP’11] Linaro Ubuntu 11.04 for ARM running in VM by KVM/ARM (Cortex-A15 in Fast Model 6.1) OS-level virtualization 24/30
- 25. Mobile Virtualization • Embracing all apps in a unified market • iOS + Android + Windows • Technically possible, but not yet by industry • Currently, not much attractive. • Multiple Androids • Android + RTOS • Issues • Performance, performance, performance… • Graphics acceleration Challenging • CPU, memory limitation • High-end smartphones can resolve this limitation 25/30
- 26. Basic Terminologies • Types of VMMs • Type-1 vs. Type-2 • Virtualization methods • Full-virtualization vs. Para-virtualization 26/30
- 27. Type-1 vs. Type-2 • Depending on what sits right on HW Guest VM Guest OS Host OS VMM HW Guest VM Guest OS VMM Guest VM Guest OS HW Guest VM Guest OS Type-1: VMM on HW Type-2: Host OS on HW • Xen, VMware ESX server, Hyper-V • Mostly for server, but not limited • VMM by default • OS-independent VMM • KVM, VMware Workstation, VirtualBox • Mostly for client devices, but not limited • VMM on demand • OS-dependent VMM 27/30
- 28. Xen: Type-1 VMM • Type-1 VMM • Para-virtualization and full-virtualization • Domain0 • Privileged VM for guest VM (domainU) management • Handling I/O operations requested from domainUs • Including native device drivers to directly access HW DomainU (Guest VM) Guest OS Xen VMM DomainU Guest VM Guest OS Domain0 (Privileged VM) Linux 28/30
- 29. KVM: Type-2 VMM • Type-2 VMM for Linux as a host OS • Based on HW-assisted virtualization • Linux kernel mainline (2.6.20~) Guest VM Guest OS Host OS (Linux) KVM VMM (kernel module) QEMU vCPU vCPU User space Kernel space Linux Process Linux Thread Linux Thread Linux Thread I/O emulation 29/30
- 30. Full- vs. Para-virtualization • Depending on whether OS source is modified • Full-virtualization = No OS source modification • SW-based full virtualization • Emulation • HW-based full virtualization • HW-assisted virtualization • Para-virtualization = OS source modification • Virtualization-aware OS • Bridging semantic gap between VMM and OS • Mostly for performance Today’s virtualization solutions adopt both approaches for optimized performance 30/30