Overview
Resource utilization. Efficiency. Scalability.Availability. Manageability. Security. These arethe issues that keep data center managersawake late into the night. Virtualization tech-nologies can address these concerns andbenefit the entire enterprise, but they haven’tbeen widely adopted—that is, until recently.
What’s changed? Well, for starters, the datacenter. The number of physical servers hasgrown to unmanageable proportions. Enter-prises need virtualization technologies tocompensate for the inefficiencies of increas-ing server sprawl. Linux* has taken a moreprominent role in enterprises1—handlingeverything from edge services (Web, firewall,DNS and DHCP) to middle-tier applicationand middleware; from backend database, e-mail and file serving to commercial high-performance cluster computing and enter-prise grid deployments. More and moreenterprises are also turning to Linux to helpaddress their multi-tier server consolidationissues. In addition, Intel and AMD havedesigned virtualization functionality into thelatest x86 and x86-64 processors—addinghardware support for server consolidation byenabling strict fault and performance isolation.They’ve also added functionality that enablesunmodified operating systems to run concur-rently on the same physical machine.
In this rapidly changing landscape, Linuxvendors such as Novell have recognized thepossibilities for data center transformation.These organizations are now releasing a newgeneration of products designed to integratevirtual machines—increasing efficiency andmanaging resources in ways that wereunforeseen just a few years ago.
Novell is committed to the propagation of Xen*virtualization technologies. These technologiesare included in the release of SUSE® LinuxEnterprise Server 10, the latest open sourceserver operating system from Novell®. Thisunique opportunity for Novell to take a lead-ing role in the shift to virtualization-based IT is due to the convergence of commodityhardware and open source software—that is,Linux running on x86 and x86-64 computers.It’s a combination that is transforming racksof compute and storage servers into the pre-eminent enterprise IT platform. Virtualizationis also differentiating applications as theyevolve into self-contained modular services.Xen virtual machines take that evolution onegiant step further.
SUSE Linux Enterprise Server 10 and Xenvirtualization technology—coupled with open-standards-based management solutions and identity-driven, directory-based technol-ogies—enable your data center managers to treat all the hardware and software in thedata center as a pool of interchangeableresource components. In effect, the technol-ogy now exists to dynamically bring togetherwhat you need, when you need it, and inways that make sense for your business.
Lose Servers, Gain the Upper Hand
There’s a reason why the typical data centercontains a sea of servers, each running asingle application: isolation minimizes theimpact of crashes. A buggy application run-ning on its own server can only bring itselfdown. A bad fan, a disk failure, or an I/Oproblem will only affect the one applicationthat’s dependent on the defective hardware.Besides, single applications running on ever-more powerful hardware leave nothingto chance regarding headroom. The set-upmay be inefficient, but it works.
So, if you decide to use virtualizationtechnologies to consolidate resources andimprove resource utilization, they must pro-vide the same level of application-workloadisolation, fault isolation and tolerance, andheadroom as the current data center config-uration. In other words, if you have severalvirtual machines (VMs) running on a singlephysical machine, the performance of oneapplication (or lack thereof) must not affectthe others, and administrators must knowthat they won’t come up short with regard toCPU cycles, memory, I/O bandwidth or othernecessary system resources. SUSE LinuxEnterprise Server delivers high-availabilitycomponents that help ensure service levelavailability—even when virtualized—thussatisfying the requirements of the moderndata center environment.
SUSE Linux Enterprise Server 10 running onXen delivers VM isolation for both softwarefaults and varying workloads. By combiningthis VM isolation in a failover cluster thatintegrates commodity hardware, enterprisescan achieve a high level of fault tolerance for hardware failures as well. Furthermore,working hand-in-hand with other softwarefrom Novell and partners, full-scale integrationof virtualization technologies is possible—across physical and virtual servers, SANsand I/O—allowing resources to be pooled,allocated and utilized like never before.
Virtualization Primer
Virtualization refers to the pooling of ITresources in a way that masks the physicalnature and boundaries of those resourcesfrom resource users. In more concrete terms,virtualization is the decoupling of softwarefrom hardware. It is the abstracting of thesoftware from the underlying implementation.(For a more detailed overview, please readthe Novell white paper “Virtualization in theData Center,” located at: www.novell.com/collateral/4622015/4622015.pdf)
With regard to Xen, there are two primaryvirtualization models:
Full Virtualization. In this type of virtualiza-tion, a full platform is emulated by meansof hardware or software—or a combinationof both—in order to support an unmodifiedoperating system. With this method, there’sno need to customize the guest operatingsystem. However, since the operatingsystem was designed to run on physicalhardware, it’s not aware of the VirtualMachine Monitor—also known as the“hypervisor.” As a result, the VM can’tcooperate with other VMs to shareresources and optimize performance.
Paravirtualization. Unlike full virtualization,paravirtualization only partially emulateshardware. The hypervisor is supplementedby APIs that assist in abstracting theunderlying hardware resources to thevirtual machine. Paravirtualization requireshardware-dependent portions of the guestoperating system to be modified to becomeaware of the virtualization layer. Currently,depending on the specific usage case,paravirtualized VMs can outperform fullyvirtualized VMs.
One of the benefits of Xen 3.0, as included inSUSE Linux Enterprise Server 10, is supportfor both paravirtualized and fully virtualizedVMs when the physical server is based onthe latest x86-based processors from Intel*(Intel VT) or AMD* (AMD-V). These proces-sors feature in-silicon virtualization technologythat works with Xen 3.0, giving you a choiceof virtualization models to meet your specific needs .
Xen Rises to the Occasion
Xen 3.0 is a virtual machine monitor (VMM)or hypervisor. It is a software foundation that governs operating systems’ access tocomputer resources, such as memory andnetwork adapters, in order to securely executemultiple VMs—each running its own operatingsystem on a single physical system.
Developed by engineers at the University of Cambridge as an open source project,Xen is the industry’s fastest and most secureserver virtualization software technology. It hasbeen endorsed and adopted by more than20 of the industry’s major vendors, includingAMD, Dell, Hewlett-Packard, IBM, Intel, Novell,Red Hat and Sun Microsystems. BecauseXen technology is open source, it has contin-ued to attract more and more contributors—essentially becoming an open standard. As a result, many companies are now build-ing commercial toolsets for Xen virtualmachine management.
Novell contributes four times more code tothe Xen project than any other Linux vendor.And now, with the release of SUSE LinuxEnterprise Server 10, Novell stakes its claim asthe first enterprise Linux distribution vendorto integrate Xen into the operating system.
With the Xen code and management toolsthat ship as part of SUSE Linux EnterpriseServer 10, you can run multiple operatingsystems on the same physical server withminimal performance impact. As a result,you can significantly increase server utiliza-tion, reduce server sprawl and lower costs.SUSE Linux Enterprise Server 10 and theXen 3.0 virtualization engine afford impres-sive new levels of resource utilization andimprovements in availability, manageability,scalability, performance, application securityand much more.
Xen currently runs on x86 and x86-64 sys-tems. Ports are currently underway to IA-64and PPC. Ports for other platforms are alsotechnically possible and may be available in the future.
Deployment and Managementof Virtual Machines
The Xen hypervisor and related tools enablecontrol of the resource abstraction layer,virtual machine lifecycle management andphysical resource reallocation. In effect, Xen is a base technology that can distributeand control the available physical resourcesof a system.
SUSE Linux Enterprise Server 10 simplifiesvirtualization technology management withYaST, a comprehensive installation, con-figuration and administration suite that isintegrated into the SUSE Linux Enterpriseplatform. YaST gives IT administrators acommon foundation for managing operatingsystem components as well as accompany-ing services and third-party applications.YaST is ideal for creating virtual machineprofiles and configuring individual VMsbecause it takes you through the same seriesof screens that you use to provision a physicalmachine. Novell ZENworks Linux Manage-ment complements YaST by enabling ITadministrators to centrally control how theydeploy and update systems?or virtualmachines?inside the firewall. By using YaST and ZENworks Linux Management,administrators can easily install, configure,update, secure and manage SUSE LinuxEnterprise Server 10 and the virtual machinesit hosts. Administrators can also start up,shut down or suspend virtual machine oper-ating system instances and migrate VMs fromone physical server to another in order torelocate a load or prepare for maintenance.
Novell engineers are currently working onhigher-order management tools, includingcentralized mechanisms to oversee Windows*,Linux and UNIX* systems. The goal is toschedule prioritized virtual machine-basedworkload units intelligently and automaticallyacross available pooled physical resources.SUSE Linux Enterprise Server 10 is thefoundation for this vision.Use Cases for XenVirtualization TechnologyLet’s take a look at some of the ways Xenvirtualization technology can be used to lowercosts, increase flexibility, simplify managementand ensure reliable operations. We’ll look atseveral methods for using Xen in the areasof server consolidation, on-demand comput-ing, highly available computing and managed-resource quality of service (QoS).
Key Virtualization Benefits
Server Consolidation
Use up to 80 percent of server capacity(instead of the five to 40 percent utilizationtypical of most servers).Reduce the number of servers required andgain square footage for other purposes.Minimize overall hardware costs.Reduce costs through reduced coolingrequirements, lower power bills anddecreased management.
Dynamic Provisioning
Dynamically grow or shrink resourceswithout physically dedicating them to aparticular application.Avoid paying for extra hardware just tomeet temporary peak demands.
Virtual Hosting
Efficiently leverage available hardwareresources and provision them in a dynamic,controlled manner.Take advantage of automation and fine-grained control of resources to lower thecost of service offerings, as well as youradministrative and hardware costs.
Reliability, Availability and Security
Support automated application failoversolutions that do not interrupt service toproduction environments.Isolate applications in containers thatminimize vulnerabilities and provide out-standing protection against hacking.Protect applications from unproven or defective applications by isolatingapplication libraries, services and operatingsystems.
Dynamic Scalability
Add more processing power by automat-ically deploying VM images on existinghardware to handle the temporary increasein demand.Shut down additional VMs when peakdemand subsides, reallocating resourcesto other activities on the network.
Improved Workload Management
Decouple applications from the underlyinghardware in order to allocate resources?CPU cycles, memory, bandwidth?according to dynamically changing needs.Run multiple operating systems on a singleserver to increase productivity and enablemore in-depth development and testing.Free up servers for additional projects.
High Availability and Non-Stop Maintenance
Migrate a virtual machine?while it’srunning?from one physical server toanother without interruption.Perform maintenance in a productionenvironment during regular business hourswith zero downtime.
Streamlined, Enhanced Test/Deploy Cycles
Minimize the need to handle different,physical machines when testing interde-pendent applications, operating systemsand physical servers.Use VMs to contain and control unstable or test configurations, avoiding disruption to other services.
Greater Operational Agility
Drastically reduce server-provisioning time.Allocate resources according to businessneeds.Free IT staff to work on a more productive,efficient and agile data center.
Novell Is Putting It All Together
“Our strategy is to build a Linux plus Novelland open source-based platform that offersdifferentiable value through sophisticatedintegration of otherwise isolated components…Consider the evolution of computing frommainframe to mini to client/server. Nowmodularize, standardize, commoditize andvirtualize. Next add integrated intelligence,and you have a modern “computer” compris-ing virtualized compute and storage that iscontrolled by a distributed operating system…”?”Virtualization, Utility Computing and Grid,”Novell, Inc., Wipfel et al.
Virtualization changes everything. Your tradi-tional notions about installing or patching aserver, for example, are radically challengedby the realization that the physical servermerely represents anonymous hardware on which virtual machines can run. You canperform installations and apply patches tooffline operating systems completely distinctfrom any particular hardware you might even-tually choose to run your virtual machine.
Xen virtualization technology and the cluster-ing capabilities integrated into SUSE LinuxEnterprise Server 10 provide the foundationfor some remarkable developments in thedata center. Developments that can takeplace now.
Today’s SANs and intelligent storage serversmake it possible to dynamically provisionand re-provision network storage. Standardssuch as CIM-based SMI-S permit software,rather than humans, to provision, assign andmanage network storage. So, opportunitiesnow exist to automate storage provisioningand shared-disk authorization to computeservers hosting virtual machines. By combin-ing virtual machines with virtualized storage,you can feasibly deploy applications intodedicated virtual servers that are scheduledacross compute and storage hardwarebased on availability of resources.
When you unite virtual machines, virtualstorage, resource management and identitymanagement, you get a comprehensive anddynamic data center management solution.
Nearly all the pieces are in place. With Xen virtualization technology incorporated intoSUSE Linux Enterprise Server 10 andthe Novell commitment to standards?in particular CIM-based, data center-classmanagement tools?it’s only a matter oftime before Novell and partners deliver anadaptive, policy-based, identity-driven com-pute environment that is entirely responsiveto business needs.
Contact a sales representative for moreinformation, or visit www.novell.com/datacenter to learn more about Novell Data Center solutions.
