As SAP systems have grown from central transactional systems for core business functions to a full featured suite of business applications, the complexity of implementing and maintaining an SAP landscape has grown. Virtualization — loosely defined as the practice of simulating an operating system, server, storage or resource for efficient sharing of computing resources — offers several ways to reduce that complexity and save money during an SAP upgrade.

Lon Blake, upgrade principal at SAP, says virtualization is increasingly popular among SAP companies, especially among those  at or near an end-of-life cycle with their server hardware. Blake, a key presenter at the SAPinsider SAP ERP Upgrade & Enhancement Packages seminars (see sidebar) this year, says companies take various approaches to virtualization.

“Most of the customers I talk to — if they’re moving in that direction — are virtualizing their development environment, their quality assurance (QA) environment, sandboxes, or training systems. From a production standpoint, if they’re doing virtualization, most are doing it from application servers and dedicating the central instance and database on a physical box,” says Blake, though he adds that some companies are taking a more aggressive tack in their virtualization plans. “I’ve talked to a few customers recently who have taken the leap of faith and virtualized the production central instance and database as well. We’re starting to see more acceptance of it.”

“From a TCO standpoint, virtualization is worth investigating,” he says. “The key is to not just go with the flow because everyone else is doing it, but to make sure it’s right for your business.”

According to Blake, the primary challenges that drive companies to virtualization are:

• Insufficient server utilization

A typical SAP landscape may include one server per application, a setup that companies have historically used to guarantee applications get all the computing power they need. However, as servers become more and more powerful (and memory becomes cheaper) this paradigm can do more harm than good. Blake says many companies are delivering far more computing power to an individual application than would ever be necessary — a scenario which not only wastes money in hardware costs but also delivers inefficient results.

• Complex IT landscapes

When Blake started working with SAP, most SAP landscapes were relatively simple. A company might have dedicated servers for the production environment, development environment, and QA environment, plus small application servers for applications attached to the central SAP system. Today, however, a typical company may also be running large applications such as SAP NetWeaver Business Warehouse (SAP NetWeaver BW), SAP NetWeaver Portal, or SAP Customer Relationship Management (SAP CRM).

“Now you’re talking about a three-tier landscape for each of those environments, plus application servers connected to all of your production boxes. You’re starting to see SAP taking over the data center,” says Blake. “Virtualization allows you to reduce that footprint by making fewer boxes serve more needs.”

• Low flexibility to assign and utilize hardware resources

One of the problems with the single server per application arrangement is that adding a new application requires the installation of new hardware. In a virtualized environment, available space can be used to set up a new virtual application server in minutes, says Blake.

• High effort to set up and integrate new components into existing infrastructure

The more complex the environment, the more difficult it is to ensure that all moving parts work well together. Adding new components to a complex infrastructure can result in unforeseen issues, whereas virtualization allows you to plug in new functionality without as much integration work.

Four Approaches to Virtualization

Virtualization can mean many different things relative to an SAP landscape. It can mean multiple virtual resources (or applications) sharing a single hardware resource, multiple hardware resources supporting a single virtual resource (or application), or a virtualization resource that emulates a hardware resource (such as storage).

According to Blake, the relevant approaches to virtualization in an SAP landscape are hardware partitioning, virtual machines, virtual operating systems, and virtual applications.

Hardware Partitioning

Hardware partitioning is the process of dividing a single server into discrete computing partitions, each of which can support its own operating system and application (Figure 1). The benefits of hardware partitioning include the ability to isolate applications in order to use only the computing resources you need.  

Figure 1

Hardware partitioning allows for multiple operating systems and applications on a single server

Virtual Machines

Similar to hardware partitioning, a virtual machines approach allows you to run multiple applications and operating systems on a single physical server. The difference is that virtual machines require the use of a software layer called a hypervisor that sits below or above an operating system (Figure 2). The benefits of virtual machines include a greater degree of granularity for allocating hardware resources.

Figure 2

The hypervisor in a virtual machine can reside directly on the server or on top of an operating system

Virtual Operating Systems

Some operating systems allow you to run applications in partitions with their own names, IP addresses, and storage resources (Figure 3). If you have multiple applications that are compatible with the same operating system, this approach can provide an efficient use of resources.

Figure 3

A virtual operating system approach can use a shared operating system to run virtually partitioned applications

Virtual Applications

In this approach, applications are decoupled from the underlying operating system (Figure 4). The benefit of this approach is that it requires no additional investment in virtualization technology and adds no additional performance overhead.

Figure 4

Virtual applications can be run from a standard operating system with no additional investment

The SAP Adaptive Computing Controller

SAP offers a customized approach to virtualization called the SAP Adaptive Computing Controller, which does not depend on any particular hardware or operating system (Figure 5). According to Blake, the primary advantage of the SAP Adaptive Computing Controller is that it is specifically tailored to make multiple SAP instances run more efficiently. By virtualizing whole instances of SAP, you can move entire instances from one physical server to another with minimal downtime — a potentially large cost savings.

Figure 5

An overview of the SAP Adaptive Computing Controller

The SAP Adaptive Computing Controller can also be used in conjunction with other virtualization approaches, says Blake. “For example, you can have instances where you virtualize at the operating system level and are running the SAP Adaptive Computing Controller. So in addition to being able to dynamically call up CPU and memory, you can dynamically reallocate your SAP instances,” he says.

SAP is currently in the ramp-up phase of SAP Adaptive Computing Controller 7.2, and is scheduled to release this version in late June 2010.

Considerations for Virtualizing Your SAP Landscape

No matter what approach you end up following, Blake identifies several tips for an effective virtualization strategy:

Keep your hardware vendor close

Because hardware is a key component of many virtualization projects, Blake recommends keeping a close relationship with your hardware vendor from the outset. “When it comes down to deciding which virtualization approach you’re going to use, you need to have a good conversation with your hardware vendor,” he says.

Even if you’re working with a systems integrator that will direct your upgrade project, Blake says it is best to maintain full control over your own technological infrastructure. “I’ve always considered that to be an in-house responsibility. You lose control if you cede that power to a systems integrator.”

Have the right in-house resources

Having a strong infrastructure team is critical to a successful virtualization initiative, says Blake. Virtualization does not usually require any specialized skills, but you should allow your team ample time to get up to speed, says Blake.

“You basically just need a good infrastructure team who has time to do homework on virtualization in conjunction with a vendor. You can bring in subject matter experts from a vendor, but I firmly believe you need a strong staff in-house. If they’re up on the latest technologies, they’re going to be ahead of the game anyway,” he says.  

Give yourself enough time

As with many SAP projects, time pressures can mount more quickly than anticipated. While virtualization can save plenty of time and money in the long run, it is not a project you should rush into, says Blake.

“The biggest mistake people make is that they don’t give themselves enough time to do these projects,” he says. “You’re dealing with new technology, so you need to give yourself enough time to implement that technology and to make sure you’ve got things tuned. Don’t think you can just bring in new hardware and migrate your stuff over and have everything up and running in three weeks. You’ve got to give yourself time to plan, prepare, and communicate.”

Davin Wilfrid

Davin Wilfrid was a writer and editor for SAPinsider and SAP Experts. He contributed case studies and research projects aimed at helping the SAP ecosystem get the most out of their existing technology investments.

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