Technical White PaperWORKGROUP COLLABORATION

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Novell® Open Enterprise Server 2: Deploying VirtualizedNetWare® on Linux*

p. 1

Novell Open Enterprise Server 2: Deploying Virtualized NetWare on Linux

2 . . . . . Taking Advantage of NetWare Virtualization

2 . . . . . Virtualization Basics

3 . . . . . Enhanced for Virtualization

4 . . . . . The Same NetWare, New Opportunities

5 . . . . . Getting the Most Out of Hardware

6 . . . . . Deployment Considerations

8 . . . . . Installing Virtualized NetWare

11 . . . . . Strategic Deployment,Greater Savings

Table of Contents:

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Taking Advantage of NetWare® Virtualization

Virtual machine technology has beenavailable for many years. It appeared first on mainframe systems, and then graduallymade its way onto personal computers.Today, virtualization has transitioned intomainstream operating systems such asLinux* and Windows* and has madesignificant inroads into the data center.

Over the past year, enterprise IT managershave become increasingly excited aboutSUSE® Linux Enterprise Server 10 fromNovell® and the many benefits provided byits included Xen* virtualization technology.Among these benefits are server consolida-tion, workload isolation and disaster recoverythrough dynamic server migration—all ofwhich are motivating more organizations to migrate to Linux. Many such enterprises,especially those that want a gradual migra-tion, are choosing Novell Open EnterpriseServer 2. It’s a Novell solution that includesSUSE Linux Enterprise Server 10, inherits itsvirtualization capabilities, and for the firsttime makes virtualization natively availablefor NetWare on Linux.

Why is this feature so important? There aremany reasons. By virtualizing NetWare onLinux, you can take advantage of an open,contemporary platform for mission-criticalcomputing without losing essential NetWareapplications and skill sets. If you want tomigrate to Linux gradually, you can leverageyour existing applications throughout theprocess. And, you can continue runningNetWare while consolidating systems ortaking advantage of the most up-to-date and innovative hardware available. NovellOpen Enterprise Server 2 makes NetWarevirtualization on Linux feasible and profitablewhile simplifying the process of wide-scaleLinux migration.

Virtualization Basics

Xen Technology

With Novell Open Enterprise Server 2, youhave the choice to deploy NetWare 6.5 SP7on a physical machine or in a virtual machineusing the Xen 3.0 technology included withSUSE Linux Enterprise Server 10. The Xensoftware layer is developed and maintainedby the Xen open source community.

Like most virtual machine technologies, Xen 3.0 consists of a host (also known asDOMAIN 0) and multiple guests (also knownas DOMAIN Us). The host is responsible forpartitioning a physical server and, as guestvirtual machines start and boot their operat-ing systems, it assigns physical resources to each guest.

Some resources, such as memory, arededicated to the guest and cannot be sharedamong guest operating systems. Otherresources, such as network cards, can beeither shared among guest operating systemsor dedicated to a specific guest.

Paravirtualization

Xen 3.0 has an advantage over many com-peting virtualization technologies because it includes a hypervisor, also known as avirtual machine monitor, as part of the corevirtualization layer. The hypervisor allowsspecially modified guest operating systemsto interact more efficiently with the physicalserver. This is known as paravirtualization.

While the host controls memory resourcesand which physical or virtual devices thevirtual machines can access, the hypervisorallocates and schedules the central process-ing unit (CPU) resources during runtime for

By virtualizing NetWare

on Linux, you can take

advantage of an open,

contemporary platform for

mission-critical computing

without losing essential

NetWare functionality

and skill sets.

Portions of this paper

originally appeared in

the Novell Connection

Magazine article titled

“Squeeze: Managing

NetWare on a Virtual

Machine” by Ken Baker.

p. 3

Novell Open Enterprise Server 2: Deploying Virtualized NetWare on Linux www.novell.com

the different virtualized guest operatingsystems. It also enforces the proper level of protection between virtual machines. The hypervisor presents the guest operatingsystems with virtual machines that performvery much like the guest servers’ nativearchitectures. With the hypervisor, then, a para-virtualized operating system can leveragevirtualized drivers rather than physical drivers.

A fully virtualized operating system has to “trap” information from the executinginstruction stream; however, a paravirtualizedoperating system does not require informationtrapping and provides performance gains asa result. In addition, with paravirtualization, thevirtualized platform is not required to emulatethe actual hardware platform. This leads to additional efficiencies in circumstancessuch as accessing page tables that controlmemory. Non-modified guest operatingsystems that operate in full virtualizationmode do not deliver these benefits.

Enhanced for Virtualization

The NetWare 6.5 operating system in Novell Open Enterprise Server 2 has beenenhanced to recognize when it is running ina virtualized environment, allowing it to runas a paravirtualized guest operating systeminside a virtual machine. As a result, virtual-ized NetWare users can enjoy all of theperformance and efficiency benefits thatparavirtualization provides.

Virtualized NetWare also lets you takeadvantage of the latest advances inhardware technologies. Some users havestruggled to find NetWare driver support oncertain new technologies, but since NetWarecan run as a paravirtualized guest operatingsystem (OS) that loads virtual drivers,physical driver support is no longer an issue.Instead, the host OS dictates the physicaldriver requirements. Because the host OS is Linux, which has comprehensive andconstantly growing driver support, para-virtualized NetWare automatically inheritsthat entire driver base.

Even though NetWare virtual machines can automatically load virtual drivers, admin-istrators still have the option to load physicaldrivers. Utilizing physical drivers lets a virtualmachine interact directly with the physicalhardware. One reason you might considerloading a physical driver is that your systemcould gain a small amount of extra perform-ance from the physical server’s networkcard. However, a more likely reason to loada physical driver would be to allow directinteraction with a tape backup device toreduce input/output (I/O) overhead. Regard-less of the reason for using physical drivers,administrators should be aware that utilizingphysical drivers can impact some virtualiza-tion operations, such as migrating a virtualmachine from one physical server to another.

The NetWare 6.5

operating system in

Novell Open Enterprise

Server 2 has been

enhanced to recognize

when it is running in a

virtualized environment,

allowing it to run as a

paravirtualized guest

operating system inside

a virtual machine.

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The Same NetWare, New Opportunities

NetWare has been enhanced to recognizethat it is running as a virtual server, but it isstill the same NetWare that your organizationhas known and trusted for years—it’s simplyoperating in a new environment that presentsadvanced opportunities and capabilities. In fact, paravirtualized NetWare utilizes thesame binary code that runs on bare metalmachines with just a few exceptions.

1. Loader file—Physical NetWare utilizeseither DOS or NWLOADER.SYS, whilevirtualized NetWare uses XNLOADER.SYS to alert the server that it’s running in avirtual environment.

2. Pre-loaded drivers—In a virtual NetWareenvironment, you will typically load virtualdrivers that interact with Xen rather thandiscrete drivers that interact with actualphysical components. These virtual drivers are primarily contained in the files XENBLK.HAM, XENNET.CAD andXENMP.PSM.

According to Novell engineering, more than 95 percent of the NetWare loadablemodules (NLMs) in NetWare required nochanges to run on a NetWare virtual machine.When changes were needed, it was typicallybecause the NLMs contained privileged orsensitive CPU instructions, accessed hard-ware directly or expected to run at ring zero.This was the case with the SERVER.EXE file,which required the most changes. This meansthat you shouldn’t have problems runningyour third-party NLMs unless they fall into oneof these categories. Novell is also workingclosely with backup and antivirus vendors to ensure that their NLMs will run withoutproblems in a virtual environment.

From a management standpoint, youradministrators can manage NetWare in avirtual machine just as they would manageNetWare on a physical machine. Traditionaltools such as Novell ConsoleOne®, NovelliManager and Novell Remote Manager(NRM) are still effective, but Novell OpenEnterprise Server 2 gives your administrators

NetWare has been

enhanced to recognize

that it is running as a

virtual server, but it is

still the same NetWare

that your organization

has known and trusted

for years—it’s simply

operating in a new envi-

ronment that presents

advanced opportunities

and capabilities.

Figure 1. Virtualized NetWare utilizes virtual drivers, eliminating the need for physical drivers.

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Novell Open Enterprise Server 2: Deploying Virtualized NetWare on Linux www.novell.com

When NetWare servers

run as virtual machines

in Novell Open Enterprise

Server 2, they are no

longer bound by 32-bit

constraints. They can

take full advantage of

the extra processing

power, added memory

capabilities and improved

heat and energy savings

offered by 64-bit dual-

core and multi-core

processors.

additional management options. They can nowtake advantage of Linux management utilitiesand console commands because the virtualmachine is running in a Linux environment.

Getting the Most Out of Hardware

One of the major benefits of runningNetWare as a virtual machine in Novell OpenEnterprise Server 2 is that it allows you tofully utilize your existing hardware investments.Unlike some virtualization solutions, virtualNetWare doesn’t have to be deployed onservers with chipsets specifically enabled for virtualization. In fact, organizations withcurrent NetWare servers and low CPU utiliza-tion might be able to host multiple NetWarevirtual machines on an existing server toleverage the benefits of server consolidation.

By running NetWare as a virtual machine, youcan also choose to integrate high-performing

hardware into your environment. This furtherenhances your ability to consolidate serversand to take greater advantage of 64-bitprocessors. When NetWare servers run asvirtual machines in Novell Open EnterpriseServer 2, they are no longer bound by 32-bitconstraints. They can take full advantage ofthe extra processing power, added memorycapabilities and improved heat and energysavings offered by 64-bit dual-core andmulti-core processors.

In addition to allowing you to preserve yourNetWare services on today’s high-end hard-ware platforms, server consolidation is oneof the main reasons for employing virtualizedNetWare. For example, with NetWare virtualmachines in a Novell Open Enterprise Serverenvironment, you might consolidate three ormore physical NetWare servers into guestvirtual machines that run on a single physicalbox. Additionally, Linux virtual machines canbe hosted on that same hardware.

Figure 2. Before and after server consolidation.

Hosting both Linux and NetWare as virtual machines on a single box can facilitate migrationefforts. Specifically, you can preserve applications and services dependent on NetWare whiletransitioning your IT environment and skill sets to Linux. To help with these consolidationefforts, you can leverage the included Novell Open Enterprise Server Migration Tools.Additional migration resources are available online at: www.novell.com/oesmigrate

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Deployment Considerations

Before implementing any changes to an IT infrastructure, research is very important.When considering virtualization, you shouldcarefully analyze your options and identifythe servers and workloads that represent thebest candidates for a virtual environment.

When to Virtualize

In environments where any of the followingconditions exist, it makes sense to beginconsidering a virtualization strategy:

Space is at a premium in the data centerand more servers need to be deployed.Overall power and cooling costs for the datacenter are running very high and need tobe reduced.A number of servers are reaching the endof their lives and need to be moved to adata center.Rolling out a new server operating systemwill take a long time from test to production.Server maintenance costs are high andneed to be reduced.Pre-deployment test cycles are needed.

In terms of power, space and cooling, virtual-ization can save a data center significantamounts of money. For example, a businessmight have eight physical servers deployedin its data center, with four servers acting asa primary service and four servers acting asa backup. In this scenario, the four backupservers could easily be moved to a virtualizedenvironment on a single physical server.

When Not to Virtualize

When laying out a virtualization strategy, anoften-overlooked question is “what shouldnot be virtualized?” Because of unpredictableutilization patterns, including servers that runat or near maximum capacity, the followingscenarios might not be the best candidatesfor moving to a virtual machine environment:

A new generation multi-core server is beinginstalled to increase the performance of a database.Current megabit switches are no longerfast enough to handle the network traffic to a server.More storage needs to be purchased as aresult of a new application generating filesthat are hundreds of megabytes in size.

While servers in these scenarios can be vir-tualized, the inherent differences in perform-ance or scalability between the physical andvirtual world might mean that you should lookelsewhere for viable virtualization candidates.

Workload Analysis

If you are hosting multiple virtual machineson the same physical server, you need to payattention to their workload types. A physicalserver that is overloaded with multiple virtualmachines with the same type of workloadcould run out of CPU power, memory or I/Obandwidth. For example, if all of the virtualmachines perform disk-intensive operations,they could use the entire bandwidth of theserver’s disk array.

To determine a good candidate for virtuali-zation, it is important to analyze the actualworkload of the server itself. To determinethis workload, the following factors must be observed:

Average CPU utilization as a percentageof available CPU resourcesMaximum CPU utilization, including peakdurationAverage network utilization as a percent-age of available bandwidthMaximum network utilization, includingpeak durationAverage memory utilization as a percent-age of available memoryPeak memory utilization, including peakduration

To determine a good

candidate for virtuali-

zation, it is important

to analyze the actual

workload of the

server itself.

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Novell Open Enterprise Server 2: Deploying Virtualized NetWare on Linux www.novell.com

A server that averages

between 2- and 7-percent

CPU utilization with an

occasional peak could

work well in a virtual

machine environment.

Disk channel utilization, as a compositeof points

Note: Disk channel utilization should be acomposite of data points that include thenumber of reads and writes performed,overall data throughput and numbers of files read and written to the disk.

Ideally, a workload analysis would beperformed over a period of several days or weeks, with the data averaged over thatperiod. When averaging the data, pay atten-tion not only to the data points collected, but also to the times of day during whichdata was collected.

During data analysis, you should ensure that the statistics for each server are keptseparate. If results are blended, it is verydifficult to determine which of the serversactually make good candidates.

Choosing the Right Workload

By the time a workload analysis is finished,you will have a solid set of data to work withand a greater understanding of what yourservers are doing and when. Still, you will needto be able to make sense of that informationbefore you can start virtualizing workloads.

The easiest way to start this process is byexcluding servers that show high utilization in one or more of the observed subsystems.A server that consistently shows high CPUutilization or frequent peaks should be dis-counted, especially if these peaks fall duringnormal working hours. Servers with peaksthat coincide with backup and antivirusactivities or other types of housekeepingmight still be considered for virtualization.

A server that averages between 2- and 7-percent CPU utilization with an occasionalpeak could work well in a virtual machineenvironment. Of course, if the plan is to

migrate from an older system with a singlecore CPU ranging between 1.8 and 2.0 GHzto a newer dual- or multi-core system running at 2.2 GHz or higher, the CPU percentageswill be somewhat skewed. The new systemwill likely be able to handle several virtualmachines with low utilization workloads.

In addition to evaluating CPU utilization, youshould check the network bandwidth andhow it is being used. Virtualization plans thatrequire all of a server’s virtual machines touse a single network card will result in anoverall decrease in available bandwidth for each of the virtual machines. Similarly, a server that handles a fairly high load on its network card might be best left as aphysical server.

One aspect of virtualization that is often over-looked is the amount of memory required.Simply because a server has moved to avirtual machine doesn’t mean that it needsless memory. The physical host server notonly needs enough memory to run all of thevirtual machines when they are loaded, itneeds sufficient memory for the host operat-ing system as well. The amount of memoryreserved for the host will vary depending onthe number of guests that will be running.

The final element to consider when choosinga workload is the utilization of the disk sub-system. Virtual machines can use a physicaldisk, a virtual disk file or network attachedstorage (NAS). Physical disks deliver the bestperformance by far, but are also the least

One aspect of virtualization that is oftenoverlooked is the amount of memoryrequired. Simply because a server hasmoved to a virtual machine doesn’t meanthat it needs less memory.

p. 8

convenient to configure and maintain whenhosting multiple virtual machines. Virtual diskfiles are the most convenient; however, theywill generally be slower. Network attachedstorage provides the most flexibility.

Any disks attached over an Internet smallcomputer system interface (iSCSI) or via a remote mount point will work in a virtualenvironment exactly as they do in a physicalenvironment. Still, pay particular attention toutilizing the network interface card. If it has avery busy iSCSI connection, it would be wiseto consider optimizing the virtual machine to handle the heavy traffic.

Note: Using a local disk on the physicalserver for a virtual machine’s storage preventson-the-fly migration of the virtual machinefrom one physical server to another.

Scalability Considerations

Although some workloads do not lendthemselves to virtualization, buying the rightserver configuration and tuning a virtualmachine can pay dividends.

One of the simplest things you can do toensure good performance is to buy serverswith high-performing CPUs. If networkperformance is a concern, servers runningmultiple virtual machines should have multiplenetwork cards. Virtual machines can beconfigured so that each one has a dedicatednetwork card. This is particularly helpful foriSCSI connections, since it allows a dedicatedcard to carry network traffic to a storage area network (SAN) or NAS device.

Installing Virtualized NetWare

The SUSE Linux Enterprise Server 10 SP1host server will need to have at least 512 MBof RAM for the VM host server and 512 MB of RAM for the NetWare virtual machine.However, for better performance, you shoulduse a server with 2 GB of RAM or more.

SUSE Linux Enterprise Server 10 SP1 willneed to be installed and configured as thevirtual machine host server, selecting XenVirtual Machine Host Server from the PrimaryFunctions software selection category. Tooptimize the host server to manage thevirtual machines, it should be configuredwithout any Open Enterprise Server services.These should be installed on an OpenEnterprise Server virtual guest OS or aphysical NetWare installation.

To avoid running additional services on ahost server, the Print Server from the PrimaryFunctions category should be deselected.Furthermore, Novell eDirectory™ should notbe running on the host server.

After the host server installation and config-uration finishes and the system reboots,perform the following steps to finalize thehost server configuration:

1. Log in as root and change the defaultboot loader to the Xen kernel.

2. Reboot the system.3. Configure the network time protocol (NTP)

on the host server.4. Disable the Alt-Escape desktop shortcut

if using GNOME*.

After the host server is running, a virtualmachine for NetWare can be created usingone of three installation methods—each withan icon in YaST.

One of the simplest

things you can do to

ensure good performance

is to buy servers with

high-performing CPUs.

For complete details on installing NetWare virtual machines, refer to the

online documentation for Novell OpenEnterprise Server 2 at: www.novell.com/

documentation/oes2

p. 9

Novell Open Enterprise Server 2: Deploying Virtualized NetWare on Linux www.novell.com

Virt-manager provides

a console that is VM-

specific and doesn’t

allow most keyboard

commands to be

intercepted by the Linux

desktop. In other words,

most of the keyboard

commands familiar to

NetWare administrators

will work as they

always have.

Virtual Machine Manager

The “Virtual Machine Manager” optionlaunches a program called virt-manager. To create a NetWare virtual machine usingvirt-manager, click Virtual Machine Managerin YaST and select New. This will launch aprogram called vm-install that will guide admin-istrators through the creation of a NetWarevirtual machine. Virt-manager provides aconsole that is VM-specific and doesn’t allowmost keyboard commands to be interceptedby the Linux desktop. In other words, most ofthe keyboard commands familiar to NetWareadministrators will work as they always have.

Create Virtual Machines

The second option in YaST is “Create VirtualMachines,” which launches the vm-installprogram directly. One advantage of using the Create Virtual Machines option directly isthat it allows administrators to run vm-installin either pure text or graphical user interface(GUI) mode, while virt-manager requires aGUI. However, launching vm-install with thisicon bypasses virt-manager and will not resultin NetWare keyboard control. This is thereason for the instruction to disable certainshortcuts in the GNOME desktop.

Figure 3. Create Virtual Machines is one of three installation methods in YaST for creating a NetWare virtual machine.

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Response File Utility

The last installation option, which simplifiesthe creation of multiple NetWare virtualmachines by enabling unattended installations,is the “Response File Utility.” A response file is created in YaST by completing thefollowing steps:

1. Select Open Enterprise Server from the menu and then select the NetWareResponse File Utility. (This utility isinstalled automatically on every NovellOpen Enterprise Server 2 Linux server.)

2. On the Select Install Type page, set thehardware type to Virtual.

3. Select the type of server installation you are creating the response file for: new server install, server upgrade or two-part factory installation.

4. The Response File Generator will ask forinformation about the NetWare server thatwill be created as a virtual machine. Thequestions should be answered the sameway they would be if a physical NetWareinstallation were being performed. If aresponse file for NetWare 6.5 is alreadyavailable, this can also be used to gener-ate a virtual NetWare server.

If a response file is used, the install can beinitiated by:

1. Selecting Virtual Machine Manager in YaST.2. Selecting Find from the Operating System

Installation menu option.3. Browsing to the location of the response

file.

After it is opened and applied, YaST will pro-ceed with the creation of the virtual machineand the installation of the virtual NetWareserver. If a required parameter is missing in the response file, the administrator will be prompted to enter the desired valuesduring the installation. If a response file is notspecified, all of the installation informationwill need to be entered just as if a physicalNetWare installation were being performed.

For complete details on installing NetWarevirtual machines, refer to the online documen-tation for Novell Open Enterprise Server 2 at:www.novell.com/documentation/oes2

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Novell Open Enterprise Server 2: Deploying Virtualized NetWare on Linux www.novell.com

Figure 4. A response file can be useful when you need to create multiple NetWare virtual machines.

After you create the virtual machines, you can manage them using the Virtual MachineManager utility, which allows operations suchas Add, View, Start, Shut Down and TerminateVirtual Machines. Virtual machines can also bemanaged from a terminal using xm commands.

Strategic Deployment, Greater Savings

Running NetWare as a virtual machine in aNovell Open Enterprise Server 2 environment

provides you with a variety of benefits. You can preserve NetWare services and skill sets; leverage the latest hardware tech-nologies; facilitate migration to Linux; andconsolidate servers for power, cooling andspace savings. With a detailed deploymentstrategy, you can fully optimize and leverageyour virtual NetWare environment, using it to reduce costs and complexity across the enterprise.

462-002066-001 | 09/07 | © 2007 Novell, Inc. All rights reserved. Novell, the Novell logo, the N logo, ConsoleOne, NetWare and SUSEare registered trademarks, and eDirectory is a trademark of Novell, Inc. in the United States and other countries.

*Linux is a registered trademark of Linus Torvalds. All other third-party trademarks are the property of their respective owners.

Contact your local NovellSolutions Provider, or call Novell at:

1 800 714 3400 U.S./Canada1 801 861 1349 Worldwide1 801 861 8473 Facsimile

Novell, Inc.404 Wyman Street Waltham, MA 02451 USA

www.novell.com

Running NetWare as a virtual machine in a Novell Open Enterprise

Server 2 environment provides you with a variety of benefits, including

the ability to preserve NetWare services and skill sets; leverage the latest

hardware technologies; facilitate migration to Linux; and consolidate

servers for power, cooling and space savings.