Cloud adoption increases steadily but it must be remembered that adoption starts from a small base. This means that it will grow more rapidly than existing IT models but today it still represents less than 3% of overall IT spend and will remain so through 2016. The key thing to consider here is the question of how much of cloud growth will drive the cannibalization of other types of spend. Vendor software licenses, hardware financing and distribution, growth of service provider revenue, and even the movement of major IT services projects to cloud computing all have a major impact on the strategy of the IT segment, Gartner says.
" The worldwide market for public cloud services across all segments grew 20.8% to $91.4 billion in 2011, up from $75.6 billion in 2010. Infrastructure as a service (IaaS) is the fastest-growing segment of public cloud services, with a compound annual growth rate (CAGR) of 41.7% (2011 through 2016). IaaS spending will surpass $72 billion from 2012 through 2016.
" Growth in the software as a service (SaaS) market is slowing, with annual growth rates of 25.7% in 2011 and 21.3% in 2012 and a five-year CAGR of 17.4%.
" Through 2014, enterprises will have at least five competitive alternatives for x86 server virtualization infrastructure. By year-end 2015, half of the Global 100 will have at least one service for production use that they consider to be a private cloud computing service, using VMs as a basic building block.
" As of mid-2012, about 75% of installed VMs are VMware-based. VMware is even more dominant in Global 500 enterprises, which generally started virtualizing early, when VMware was the only competitor in the market. Large enterprises also heavily leverage higher-end tools, such as vMotion, and are more demanding in their production use of VMs.
" During the same period, Microsoft has grown to an approximately 18% installed base market share. Microsoft is mainly attracting newcomers to virtualization, which are still mostly smaller enterprises with deployments of 100 or fewer VMs. However, because of the very large pricing gap with VMware, Microsoft is winning some larger enterprises -- especially in peripheral roles (branches and stores).
" Citrix seems to have lost momentum for server workloads, but is gaining momentum for hosted virtual desktops (HVD). Its installed base accounts for about 5% of the VM installed base.
" The rest of the vendors -- Oracle, Novell, Red Hat and Parallels -- account for about 1% of the installed base today -- but they are growing.