Network Implications of Server Virtualization in the Data Center

Server virtualization solutions such as VMware Infrastructure are increasingly being deployed because of their effectiveness in addressing current challenges related to the cost and operation of the server environment in the data center. VMware addresses these challenges by running multiple virtual machines on a single physical server, thus increasing utilization and simplifying operations, which reduces both operating expenses (OpEx) and capital expenditures (CapEx). However, widespread deployment of virtual machines can stress data center infrastructure designed to support the traditional server model, where one application runs on one physical server. Cisco Catalyst switches and Cisco MDS 9000 family storage area network (SAN) switches address these new design requirements and support functions that deliver predictable application performance, security, segmentation, and availability for dense virtual machine environments. Introduction Server virtualization and the use of virtual machines is profoundly changing data center dynamics. Most organizations are struggling with the cost and complexity of hosting multiple physical servers in their data centers. The expansion of the data center, a result of both scale-out server architectures and traditional “one application, one server” sprawl, has created problems in housing, powering, and cooling large numbers of underutilized servers. In addition, IT organizations continue to deal with the traditional cost and operational challenges of matching server resources to organizational needs that seem fickle and ever changing. Virtual machines can significantly mitigate many of these challenges by enabling multiple application and operating system environments to be hosted on a single physical server while maintaining complete isolation between the guest operating systems and their respective applications. Hence, server virtualization facilitates server consolidation by enabling organizations to exchange a number of underutilized servers for a single highly utilized server running multiple virtual machines. By consolidating multiple physical servers, organizations can gain several benefits: ● Underutilized servers can be retired or redeployed. ● Rack space can be reclaimed. ● Power and cooling loads can be reduced. ● New virtual servers can be rapidly deployed. ● CapEx (higher utilization means fewer servers need to be purchased) and OpEx (few servers means a simpler environment and lower maintenance costs) can be reduced. Because of these compelling financial and operational benefits, the vast majority of organizations are either piloting virtual machines or have production applications running in virtual machine environments. Because of the compelling value proposition of virtual machines, some organizations are now making virtual machines their default operating environment.