Enterprises are virtualizing more and more of their workloads. The benefits are well-known: consolidation and infrastructure efficiency; faster provisioning of applications and better configuration management; universal high-availability services; automated resource optimization, and dynamic scaling of applications.\n\nHowever, even as businesses realize these benefits, many are lagging in transitioning their tier 1 applications\u2014the mission-critical apps that could benefit the most from virtualization.\n\n"What we find is that customers virtualize anywhere from 40 to 60 percent of their estate before they come to their business critical apps," says Parag Patel, vice president of alliances at VMware, though he notes that the majority of VMware customers are well over 50 percent virtualized at this point.\n\nVirtualizing Tier 1 Apps Is a Critical Step Toward the Cloud"Virtualizing tier 1 applications is critical to the success of a private cloud," Gary Chen, research manager for Cloud and Virtualization System Software at IDC, writes in a white paper:\n\n"To deliver the most value, the private cloud must encompass the majority of workloads already in use and reduce the number of fragmented resource silos that lie outside the cloud. This allows organizations to take advantage of the economies of scale for optimal infrastructure efficiency. In addition, many of the advanced features of the cloud that transform applications from static entities into dynamic IT services will be the most value to mission-critical, complex applications. For example, a simple print server will probably not benefit greatly from dynamic scaling features, but a critical customer-facing Web application would benefit greatly."\nIn many ways, virtualizing your business is a three-step process (with lots of mini-steps along the way). In general, Patel notes, businesses start their virtualization journey with IT assets and departmental servers. These businesses are seeking to consolidate infrastructure and to reduce Capex in favor of OpEx. The second step involves a focus on business production, as the business takes its business-critical assets and virtualizes them. The final step is automation, which is about leveraging virtualization for an autonomously managed and scalable infrastructure that Patel terms "Cloud-era Architecture" and IDC's Chen calls "Virtualization 3.0."\n\n"The future enterprise cloud is a fully virtualized data center," Chen writes. "It is driven by server virtualization, but in tight concert with storage, network and I\/O virtualization. Virtualization will abstract the infrastructure and present it as a service to application owners (infrastructure as a service). The cloud can offer applications uniform and universal infrastructure services, such as on-demand provisioning, automated release cycles, dynamic scaling and high availability\/disaster recovery (HA\/DR). Enterprises may also tightly couple an application runtime environment with this virtualized infrastructure to create a platform as a service offering. As virtual servers will explode in number and far outstrip physical servers, a Virtualization 3.0 data center will have a very intelligent management layer that will automate most tasks through a policy-driven, service-oriented approach."\n\nConsiderations for Virtualizing Tier 1 ApplicationsEven so, it's not particularly surprising that businesses are cautious when it comes to their tier 1 applications. The applications themselves are often the most complex and most critical to a business and questions around stakeholder buy-in, architecture, and ISV support and licensing must be addressed before taking the plunge. Unlike Tier 2 applications, which can usually be virtualized in a self-contained manner, your Tier 1 applications touch on many people, processes and technologies.\n\nPatel notes that detailed best practices for virtualizing tier 1 applications are difficult to come by because the particulars of any one company's deployment tend to be unique and often tied to another project that sparked the virtualization initiative. He points to one VMware customer that had 12 different ERP applications, acquired through mergers and acquisitions. Not only did that customer want to virtualize its ERP apps, it wanted to migrate to a single platform.\n\n"The considerations are really more about how the app has been deployed, what the architecture looks like, what the dependencies are and what the company wants to do with their underlying hardware," Patel says. "Are they aiming for a refresh or standardization on new equipment?"\n\nTools and management are another consideration. Many application vendors now offer tools specific to running their apps on virtual machines, but Patel warns the tools sometimes work differently than the tools designed to manage the apps on bare metal. Processes\u2014particularly around patching, updating and maintaining the application-are also likely to be different, so it's important understand the nuances and prepare for them before making the transition.\n\nBeyond the technical considerations, the whole culture of your IT department also requires serious thought for you to successfully make the leap to cloud-era architecture.\n\n"You've got to get your mind around this architecture," Patel says. "You've got to realize that you have to change. The old way of doing things\u2014having those computing silos and the admins and consultants around those silos-you have to move off of that. The big jump you're making mentally and operationally is going from silos to a common architecture. Most IT departments, by and large their state has been defined by what we did in the 90s. They've to realize it's now all about service levels. If you're a business department like the marketing department, you're not locked into using your company's IT department anymore. You have choice. IT departments have competition now."\n\nSteps for Maximizing Success of Virtualizing Mission-Critical ApplicationsStill, there are a number of steps you can take to maximize the odds of success when virtualizing mission-critical applications:\nTalk to your virtual machine hypervisor vendor to understand considerations specific to their platform.\nSit down with your system integrator and\/or consultants and discuss your needs in terms of architecture.\nTake stock of your current infrastructure and determine which components can support your new requirements and which ones will need an update or upgrade.\nReview your policies and processes and realign them for the virtual environment, including factors like information and application availability requirements and your need for a test and development environment.\nThink about your backup strategy and how best to schedule and manage multiple, concurrent backup jobs per server.\nRevise your management methodology to account for both physical and virtual components in a single view.\n\nThor Olavsrud is a senior writer for CIO.com. Follow him @ThorOlavsrud.