It wasn’t all that long ago that virtualization was viewed as cutting edge technology that was useful for development and testing but not for real production implementations. But the advent of hypervisor based virtualization technologies like VMware’s ESX Server and Microsoft’s Hyper-V Server radically changed that perception.
These technologies moved the support of the virtualization layer out of the operating system and put it directly on the system hardware, vastly improving the performance and stability of virtual machines. In addition, hardware improvements like 64-bit processors and, more recently, support for Second Level Address Translation (SLAT) have significantly boosted the scalability and performance that are available for virtual machines. Virtualization is now a core IT infrastructure technology. In 2012, expect to see the continued virtualization of larger and larger workloads.
One of the important virtualization trends that larger companies are pursuing is Virtual Desktop Infrastructure (VDI) or, as it’s often called, Hosted Desktop Virtualization. VDI should not be confused with desktop virtualization products like VMware Workstation or Microsoft’s Virtual PC, where the virtualization software runs on the desktop itself. With VDI, the virtualization support is provided by a back-end virtual server product such as VMware’s ESX Server or Microsoft’s Hyper-V. The physical client machine in a VDI implementation requires very little processing power and can be a legacy PC or even a thin client. The client needs only enough power to run a remote connection protocol like RDP or ICA which is routed to a target VM image running off the backend virtualization server. The benefits of VDI include greatly improved central management of clients as well as easy migration to new client OSs because VDI eliminates the need to physically upgrade the client machines. Popular VDI products include VMware’s View and Citrix’s XenDesktop.
Another trend that’s more popular in larger companies is application virtualization. Because virtualized applications must be preprocessed before they can be deployed, application virtualization tends to be used by medium and larger business and not so much by smaller organizations that don’t want to deal with the complexity. The two main application virtualization products are VMware’s ThinApp and Microsoft’s App-V. Application virtualization makes it easy to deploy new applications, and because the applications are essentially sandboxed, they don’t need to be installed on the client to run nor will they interfere with other applications that may be on the client desktop. IT assigns virtualized applications to users in Active Directory. Then when the user logs in the virtualized application is streamed to the user.
Probably the most important virtualization trend that lays the ground for the future is support for the dynamic datacenter. Most organizations are already taking advantage of virtualization for server consolidation. The next stage beyond server consolidation is the ability to move virtualized resources between different hosts with no downtime. Many organizations are already using technologies like VMotion and Live Migration to accomplish this task. The dynamic datacenter builds on this foundation by automatically moving workloads between virtualization hosts based on demand or resource utilization. Products like VMware’s Distributed Resource Scheduler (DRS), Microsoft’s VMM 2008’s Performance Resource Optimization (PRO) feature or VMM 2012’s Dynamic Optimization enable an organization to add dynamic workload optimization onto its existing virtual infrastructure.
You can’t write about virtualization today and not cover the cloud somewhere. The institution of the dynamic datacenter paves the way to the private cloud. Using virtualization to create the private cloud is the most recent and perhaps most important virtualization trend in 2012. The private cloud is more than just virtualization. Virtualization and the ability to dynamically move virtual machines and resources between hosts provide the foundation for the private cloud. However, the private cloud adds the ability to create resource pools from virtualized assets, manage multiple VMs as a single unit or service, and provide self-service capabilities and usage based resource metering. The private cloud increases IT’s flexibility and enables it to respond to user requests more rapidly. Microsoft’s VMM 2012 and VMware’s vCloud Director allow you to build private cloud infrastructures. Today implementing the private cloud is a small but growing trend that may well be the next standard for building IT infrastructure.