Virtualization-Presentation-with-History
- 2. Six Reasons Businesses NeedVirtualization Increase Server Efficiency Improves Disaster recovery Efforts Increase Business Continuity Test Security updates and Patches Move to desktop virtualization
- 5. DEFINITION In computing, virtualization refers to the act of creating a virtual (rather than actual) version of something, including virtual computer hardware platforms, operating systems, storage devices, and computer network resources A layer mapping its visible interface and resources onto the interface and resources of the underlying layer or system on which it is implemented
- 7. Virtualization contd. ◦ Purposes Abstraction – to simplify the use of the underlying resource (e.g., by removing details of the resource’s structure) Replication – to create multiple instances of the resource (e.g., to simplify management or allocation) Isolation – to separate the uses which clients make of the underlying resources (e.g., to improve security)
- 8. Virtual Machine Monitor (VMM) VMM Virtual Machine Guest OS Application Virtual Machine Guest OS Application Virtual Machine Guest OS Application Real Machine ◦ A virtualization system that partitions a single physical “machine” into multiple virtual machines. ◦ Terminology Host – the machine and/or software on which theVMM is implemented Guest – the OS which executes under the control of theVMM
- 10. Benefits and Advantages ofVirtualization Resource Utilization Reducing Hardware Costs Maintenance Multiple Systems System Security Test Environment
- 11. Architecture & Interfaces Architecture: formal specification of a system’s interface and the logical behavior of its visible resources. Hardware System ISA User ISA Operating System System Calls Libraries Applications ISA ABI API API – application Programming interface ABI – application binary interface ISA – instruction set architecture
- 13. Instruction Set Architecture Level At the ISA level, virtualization is performed by emulating a given ISA by the ISA of the host machine Guest OS gives instructions to emulator and it translates to native instructions set which executes on host machine Types of Instructions Processor oriented instructions I/O instructions
- 14. Hardware Abstraction Level this approach generates a virtual hardware environment for aVM HAL is included in form of device drivers The idea is to virtualize a computer's resources, such as its processors, memory, and I/O devices
- 15. Operating System Level Virtualization layer replicates OS installed on Physical machine to createVirtual environment for the application by partitioning for each virtual machine Application will not come to know about separation OS-level virtualization creates isolated containers on a single physical server and the OS instances to utilize the hard-ware and software in data centers The containers behave like real servers
- 16. Library Support Level(API level) Virtualization with library interfaces is possible by controlling the communication link between applications and the rest of a system through API hooks. The software tool WINE has implemented this approach to support Windows applications on top of UNIX hosts
- 17. User-Application Level Application works simply like a block of instructions Set of instructions are machine specific can be used by application level virtualization Microsoft .NET CLR and JavaVirtual Machine (JVM) are two good examples MSIL to native code
- 18. Virtualization structure Virtualization can achieved through Virtual Machine Monitor(VMM) also known as Hypervisor Software
- 21. Hosted Hypervisor(Type 2) Run guest OS on top of Host OS Performance of hosted system may be downgraded , due to I/O requests passed through host OS Host OS has full control over scheduling and other task of its applications and the VMM . VMwareWorkstation, VMware Player, OracleVirtualBox
- 22. Bare-Metal Hypervisor(Type 1) VMM is installed above it which can directly communicate with hardware used by base OS These hypervisors run directly on the host's hardware to control the hardware manages guest operating systems. For this reason, they are sometimes called bare metal hypervisors. The first hypervisors, which IBM developed in the 1960s, were native hypervisors OracleVM Server for SPARC, OracleVM Server for x86, the Citrix XenServer, Microsoft Hyper-V, and VMware ESX/ESXi.
- 23. KVM Kernel-basedVirtual Machine (KVM) is a virtualization infrastructure for the Linux kernel that turns it into a hypervisor KVM requires a processor with hardware virtualization extension
- 24. Xen is a hypervisor using a microkernel design, providing services that allow multiple computer operating systems to execute on the same computer hardware concurrently. Xen is a hypervisor that supports x86, x86_64, Itanium, and ARM architectures, and can run Linux,Windows, Solaris, and some of the BSDs as guests on their supported CPU architectures. Xen can do full virtualization on systems that support virtualization extensions, but can also work as a hypervisor on machines that don't have the virtualization extensions The University of Cambridge Computer Laboratory developed the first versions of Xen Xen supports a form of virtualization known as para virtualization, in which guests run a modified operating system
- 25. Difference between Xen and KVM XEN KVM hypervisor Type-1 Type-2 form ParaVirtualization FullVirtualization Technology Open source(Citrix) Open source origin originated in a 2003 Cambridge University research project introduced into the Linux kernel in February 2007, Emulator Dom0 QEMU
- 26. System-level Design Approaches Full virtualization (direct execution) ◦ Exact hardware exposed to OS ◦ Efficient execution ◦ OS runs unchanged ◦ Requires a “virtualizable” architecture ◦ Example: VMWare Paravirtualization OS modified to execute under VMM Requires porting OS code Necessary for some (popular) architectures (e.g., x86) Examples: Xen, Denali
- 27. BinaryTranslation with FullVirtualization VMM traps the privileged instructions coming from guest and translates using binary translation
- 28. Hardware assistVirtualization Binary Translation uses dynamic modification which causes performance degradation This is the new approach that avoids in the system state and calls the VMM directly Namely Intel-VT and AMD-V use this technology Hardware assistedVMMs interrupt the execution ofVM code only when it is extremely necessary
- 29. ParaVirtualization System virtualization method which makes OS aware that it is being virtualized OS calls underlyingVMM automatically Calling the hypervisor from the OS known as Hypercalls Modification in the source code improves the virtual system performance greatly
- 30. KVM Aim-:Virtualization using KVM Hypervisor 1) Check whether CPU has hardware virtualization support. KVM only works if your CPU has hardware virtualization support – either IntelVT-x or AMD-V.To determine whether your CP includes these features, run the following command: #sudo grep -c "svm|vmx" /proc/cpuinfo A 0 indicates that your CPU doesn’t support hardware virtualization, while a 1 or more indicates that it does. # sudo kvm-ok 2)Install KVM and supporting packages. Virt-Manager is a graphical application for managing your virtual machines.you can use the kvm command directly, but libvirt and Virt-Manager simplify the process. #sudo apt-get install qemu-kvm libvirt-bin bridge-utils virt-manager 3) Create User. Only the root user and users in the libvirtd group have permission to use KVM virtual machines. Run the following command to add your user account to the libvirtd group: #sudo add user ubuntu #sudo add user ubuntu libvirtd After running this command, log out and log back in as bvcoe 4) Check whether everything is working correctly. Run following command after logging back in as bvcoe and you should see an empty list of virtual machines. This indicates that everything is working correctly. #sudo virsh list --all #virsh -c qemu:///system list 5)OpenVirtual Machine Manager application and CreateVirtual Machine
- 32. Xen