VMware ESX Server: Scale Up or Scale Out?

This IBM Redpaper presents a basis for discussion about optimal and efficient implementations of ESX Server, the flagship VMware product for x86 hardware virtualization. We consider best practices regarding the scalability of an ESX Server implementation on IBM eServer xSeries and BladeCenter servers.

In this document, we focus the discussion on two major scenarios. The scale-up implementation applies to architecture based on one or few large x86 server systems and involves adding components and resources to the system to achieve scalability. The scale-out implementation is based on many smaller x86 server systems means adding new server systems to your “server farm” to scale it according to your needs.

We assume that readers of this paper have an understanding of the VMware products, specifically ESX Server, VirtualCenter, and VMotion.

Introduction
VMware virtual infrastructure
VMware VMotion
High availability considerations
Defining scale-out and scale-up
Scale up (fewer, larger servers)
Scale out (more, smaller servers)
Conclusions
Appendix A. Server virtualization alternatives
Appendix B. IBM Virtual Machine Manager
Appendix C. SAN considerations

Related product families

Product families related to this document are the following:

• VMware Alliance
• VMware vSphere