Virtualization: Optimized Power and Cooling to Maximize Benefits

Virtu alization:
Optim ized Power and
Cool ing to Maximize
Bene fits

By Suzanne Niles
White Paper #118 Includes Virtualization Energy Cost Calculator



Executive Summary
Data centers are routinely and unknowingly missing a great portion of their entitlement from
virtualization. Beyond virtualization's undisputed IT benefits - from reduced rack footprint
to disaster recovery - is the parallel story of a substantial benefit from optimizing the
physical infrastructure that supports it. In particular, row-based cooling, correctly sized
power and cooling, and real-time capacity management are essential elements in realizing
virtualization's full potential in cost reduction, efficiency, and reliability.
3 Introduction
4 Challenges to power and cooling infrastructure 5 Row-based cooling
7 Scalable power and cooling
9 Capacity management
12 Effect on power consumption and efficiency
22 Availability considerations
23 Conclusion
25 Appendix
©2008-2009 American Power Conversion. All rights reserved. No part of this publication may be used, reproduced, photocopied, transmitted, or stored in any retrieval system of any nature, without the written permission of the copyright owner. www.apc.com WP118 Rev 1 2Introduction
There are three primary things to understand about virtualization as it relates to the data center's power and cooling infrastructure:
. Power and cooling technology is available today to safeguard availability and meet the challenges of density and dynamic power that often accompany virtualization and consolidation.
. Power consumption will always be less after virtualizing, as a result of computing consolidation and physical reduction of the amount of IT equipment. With optimized power and cooling to minimize unused capacity (the subject of this paper), power consumption will typically be much less.
. Data center infrastructure efficiency (DCiE) will go down after virtualizing, due to fixed losses in unused power and cooling capacity. With optimized power and cooling to minimize unused capacity, power and cooling efficiency (DCiE) can be brought back to nearly pre-virtualization levels - sometimes even better, depending upon the nature of improvements to the cooling architecture.
a Virtualization can bring increased rack power density and Beyond high density
pace of change to the data center, increasing the Virtualization can result in increased rack density, but it also introduces issues that go beyond high density alone demands on power and cooling infrastructure (see and which must be considered in power and cooling sidebar). Fortunately, high density is not new, and systems supporting a virtualized environment. effective strategies for supporting it have had time to What's different now develop. While virtualization can carry consolidated and . Increased server criticality - Virtualization is bringing higher and higher processor utilization to the data dynamic computing to extraordinary new levels, the basic center, increasing the business importance of each power and cooling requirements of virtualized computing physical server, which makes effective power and cooling even more critical in safeguarding availability. are similar to those already introduced by high-density . Hot spots that vary in time AND place - With blade servers during the past decade. As a result, virtualization, applications can be dynamically started technologies are available today to meet the power, and stopped, resulting in loads that change both over time AND in physical location. This adds a new cooling, and management needs of a virtualized challenge to the architecture and management of power and cooling. environment. . Reduction in IT load - The abrupt, sometimes extreme, reduction in IT load that accompanies Physical consolidation from virtualizing will always reduce virtualization presents an opportunity for cost reduction in power and cooling systems that is often missed. power consumption in two ways: (1) Directly, from the reduced server population and (2) indirectly, from e... [download for more]