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Benefits:. Increased server utilization Reduced IT TCO Improved IT agility. Advantages:. High performances Affordable, low cost solution Robust and easy to use Easy to deploy Simple management and implementation of virtual machine
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Benefits: • Increased server utilization • Reduced IT TCO • Improved IT agility
Advantages: • High performances • Affordable, low cost solution • Robust and easy to use • Easy to deploy • Simple management and implementation of virtual machine • Multi-os support enables windows and Linux virtual machines • Board industry support amongst leading manufacturer including IBM, INTEL, HP • Wider local storage support • Deep hardware virtualization integration
Xen-Domain0 Xen-DomainU Guest OS Host OS PinTool CodeCache 2 Engine PinOS I/O Xen Virtual Machine Monitor (VMM) 1 H a r d w a r e To run PinOS between guest and hardware: Use Xen Virtualize and present a fake processor to the guest OS 1 2 XEN architecture
Processor architecture • Table 2.3 Xen Features by CPU Architecture • x86 x86 x64 • Feature (no PAE) (with PAE) (x86_64) IA-64 POWERPC • Privileged Domains X X X X X • Guest Domains X X X X X • SMP Guests X X X X • Save/Restore/Migrate X X X X • More than 4GB RAM X X X X • Progressive PV X X X X X • Driver Domains X X X
Paravirtualization • Table 2.4 Paravirtualization Requirements and Considerations • Item Type item Requirements or special Consideration • Memory Management Segmentation Cannot insert privileged segment descrip- • tors and cannot overlap with the top end • of the linear address space. • Paging Guest operating system has direct read • access to hardware-level page tables, • updates are batched or performed indi- • vidually and validated by the hypervisor. • CPU Protection The guest operating system must run at a • more restricted privilege level than Xen— • in other words, it cannot run in Ring-0. • Exceptions The guest operating system must register • a table for exception trap handlers.
Continued… • System calls The guest operating system may install a • handler for system calls, allowing direct • calls from an application or the operating • system itself. Some of these calls do not • need to be handled directly by Xen. • Interrupts Hardware interrupts are replaced with a • notification event mechanism. • Time The guest operating system must be • aware • Device I/O Network Virtual devices are simple to access. Data • and Disk is transferred using asynchronous I/O • rings, and interrupt-like communication • to the guest operating system is handled • through event notifications.
virtualization • CPU • Cpu virtualization • Cpu scheduling • Time • Memory management • Memory allocation • Paging and segmentation • Virtual address translation • I/o virtualization • Device i/o ring • Event channels • Virtual i/o devices and split device driver • Software and hardware iommu
Creating virtual machine • Using a template file • Installing from a CD or an ISO image onto a XEN virtual machine (windows 2003 and windows xp only) • Installing from vendor media onto a network installation server directly onto a XEN vm • Performing a physical to virtual convertion on an existing server • Cloning an existing VM • Importing an existing exported XEN VM
conclusion • Great performances with minimal overhead • Hardware virtualization extension • Easy to use, robust and affordable • Benefits of server utilization
REFERENCES • www.xensource.com • www.wikipedia.org • www.xenenterprise.com • www.xenserver.com • www.gosephtechnologies.com • Linux for U