C l o u d C o m p u t i n g 14 Published by the IEEE Computer Society 1089-780 1/09/$26.00 © 2009 IEEE IEEE INTERNET COMPUTING C loud computing is, to use a cloud- inspired pun, a nebulously dened term. However, it was arguably rst popularized in 2006 by Amazon’s Elastic Compute Cloud (EC2; www. amazon.co m/ec2 /), which started oer- ing vir tual machi nes (VM s) or US$0.1 0 an hour using both a simple Web inter- ace and a programmer-riendly API. Although not the rst to propose a utility computing model, Amazon EC2 contributed to popularizing the inra- structure-as-a-service (IaaS) paradigm, which became closely tied to the no- tion o cloud computing. An IaaS cloud enables on-demand provisioning o computational resources in the orm o VMs deployed in a cloud provider’s data center (such as Amazon’s), mini- mizing or even eliminating associated capital costs or cloud consumers and letting those consumers add or remove capacity rom their IT inrastructure to meet peak or fuctuating service de- mands while paying only or the actual capacity used. Over time, an ecosystem o provid- ers, users, and technologies has co- alesced around this IaaS cloud model. More IaaS cloud providers, such as GoGrid, FlexiScale, and ElasticHosts, have emerged, and a growing number o companies base their IT strategy on cloud-based resources, spending little or no capital to manage their own IT inrastructures (see http://aws.amazon. com/solutions/case-studies/ or several examples). Some providers, such as One o the many defnitions o “cloud” is that o an inrastructure-as-a-service (IaaS) system, in which IT inrastructure is deployed in a provider’s data center as virtual machines. With Ia aS clouds’ growing popularity, tools and technologies are emerging that can transorm an organization’s existing inrastructure into a private or hybrid cloud. OpenNebula is an open source, virtual inrastructure manager that deploys virtualized services on both a local pool o resources and external IaaS clouds. Haizea, a resource lease manager, can act as a scheduling back end or OpenNebula, providing eatures not ound in other cloud sotware or virtualization-based data center management sotware. Borja Sotomayor University o Chicago Rubén S. Montero and Ignacio M. Llorente Universidad Complutense de Madrid Ian Foster Argonne National Laboratory, University o Chicago Virtual Infrastructure Management in Private and Hybrid Clouds Authorized licensed use limited to: National Science Council . Downloaded on January 27, 2010 at 03:16 from IEEE Xplore. Restrictions apply.
