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Chapter 5 • Implementation Strategies 145

supports multiple types of operating systems on a single server (“Top Ten Considerations For
Choosing A Server Virtualization Technology”), (2) is relatively easy to install and use,
(3) offers true isolation of each virtual OS instance, and (4) the operating systems serving as
VMs do not need any modifications. This approach has the potential of creating significant
overhead, especially for I/O-intensive workloads such as a database. 3
Paravirtualization is similar to hardware virtualization in that it is designed to support
multiple types of OSs on a single server, while providing isolation from other OS instances
running on the server. A benefit of paravirtualization is that it provides more efficient process-
ing and lower overhead. The net result is better performance than hardware virtualization
(“Top Ten Considerations for Choosing a Server Virtualization Technology”). The drawback is
that its extra software layer exists and is complex to both install and administer. The server OS
must be modified to run with paravirtualization; some OSs may not be readily available for
this solution. 4
The virtualization method chosen will depend on the ERP system. Some ERPs limit the
choices of potential virtualization vendors. To retain full vendor support for Microsoft Dynamics
GP 2010, for instance, the two virtualization choices available are Microsoft Virtual Server and
Microsoft Virtual PC (“System requirements for Microsoft Dynamics GP 2010”). If another
virtualization vendor is chosen, Microsoft’s policy states that “Microsoft does not test or support
Microsoft software running together with non-Microsoft virtualization software” (“Support
policy for Microsoft software running in non-Microsoft hardware virtualization software”).
Oracle is utilizing the same model as Microsoft. In November 2007, Oracle released its
own virtualization software called Oracle VM. Oracle VM uses paravirtualization architecture
based on the Xen open-source technology that brings with it both Linux and Windows support
(“Oracle Virtualization introduction guide”). In early 2009, Oracle expanded its virtualization
portfolio by acquiring Sun Microsystems and Virtual Iron Software Inc (“Guide to Oracle’s
virtualization strategy”). In November 2009, Oracle announced it would only support applica-
tions running on its own virtualization software. In practice, however, Oracle is supporting appli-
cations that run in other virtual environments. 5
SAP has taken a different approach to virtualization. SAP’s strategy does not dictate what
software customers can use to virtualize their applications. SAP’s strategy for virtualization has
been to provide customers with the tools, code tweaks, and support they need to make sure their
SAP virtualization projects go smoothly. This strategy has helped SAP emerge at the front of the
virtualization pack. The company’s focus has been to remain strictly an application vendor as
opposed to a platform or infrastructure software provider. If a customer running SAP on a dedi-
cated virtualization platform confronts an issue, that customer only needs to contact SAP, and
SAP will work with those vendors to identify and resolve the issue. 6
Today’s marketplace contains many hardware and software companies offering virtualization
solutions for ERP systems. The major hardware vendors offering them are Dell, Fujitsu-Siemens,
HP, and IBM. Some of the major virtualization software vendors from VMWare, Microsoft, Citrix,

3 Berman, J. (January–March 2009). Red Hat Delivers with Integrated Virtualization Capabilities. SAP Insider, 13–14,
Print.
4 Stafford, J. (2007). Server Virtualization: Three Top Methods, Plus Pros and Cons. Techtarget.com. http://itknowledge
exchange.techtarget.com/server-virtualization/server-virtualization-three-top-methods-plus-pros-and-cons/ (accessed
July 14, 2010).
5 Beal, B. (2008). What Does Virtualization Mean for SAP Managed Hosting? SearchSAP.com. TechTarget.
6 Wartenberg, R. and Gunther S. (January–March 2009). SAP Virtualization: Partnering to Increase Flexibility, Improve
Scalability, and Reduce TCO. SAP Insider, 19 (12), Print.