By Jeanne Feldkamp, Deb McDonald and Tom Kolnowski
Once an isolated island reserved for test and development, virtualisation is helping organisations to unlock their untapped server, storage, and networking resources.
Soaring energy prices have hit business where it hurts: in the bottom line. Because power is often the single largest data centre operating expense, executives are searching for ways to increase the cost-effectiveness of IT infrastructures, often by upgrading to equipment designed for high energy efficiency. Still, unless performance per watt increases or energy prices decline, data centre power and cooling costs are likely to overtake hardware costs in many organisations.
At the same time that executives are under pressure to cap data centre power consumption, they are facing exponential growth in demand for processing power and data storage capacity.
Enterprises need to confront the issue of efficiency within the overall IT infrastructure.
Exacting service-level agreements also create pressure to heighten system availability and resilience. In addition, legacy data centres usually lack the proper design, build, infrastructure, or location characteristics to support emerging regulatory and business requirements.
For many organisations, these factors mean only one thing: additional data centres. Unfortunately, additional data centres compound IT power costs and add complexity to already-complex global enterprise networks.
In some cases, data centre expansion follows merger or acquisition activity, which brings the extra complication of integrating heterogeneous and sometimes overlapping software environments.
Server consolidation can begin to address the problem of climbing data centre power costs and complexity. But containing server sprawl is just a first step. Enterprises also need to confront the issue of efficiency within the overall IT infrastructure.
Based on a traditional model of one application per server, up to 80 to 90% of x86 computing capacity may be unused at any one time - and this unused capacity needs to be managed. It takes up data centre space, and it requires power and cooling.
Exploring x86 virtualisation technology
Virtualisation technologies in the x86 world, once an isolated island reserved for test and development environments, are now gaining traction as a mainstream choice for the enterprise IT infrastructure.
Virtualisation techniques have the potential not only to unlock underutilised server capacity, but also to expedite software deployment, reduce downtime, enhance disaster recovery, enable variable usage accounting and charge-backs, support holistic enterprise-wide capacity planning, and dampen the effects of skyrocketing energy costs.
At the heart of virtualisation technology are hypervisor architectures, that is, virtualisation platforms or virtual machine (VM) monitors that allow multiple occurrences of operating systems - VMs - to run on the same physical host computer at the same time. Hypervisors use a thin layer of code to help achieve fine-grained, dynamic resource sharing and are generally categorised into two distinct camps:
• Type 1 hypervisor:The virtualisation software is, in effect, a purpose-built OS that runs natively on the hardware platform for the sole purpose of hosting and managing VMs. Once the type 1 hypervisor is running on the hardware platform, multiple VMs can be hosted on top of it as guests - these may be Microsoft Windows, Linux, or other standard operating systems. Type 1 hypervisors fall into two subcategories: those with hardware emulation virtualisation (where the hypervisor interacts with the VM through a hardware emulation layer) and those with paravirtualisation (where the hypervisor interacts with the VM through a special application programming interface). An example of a type 1 hypervisor with hardware emulation virtualisation is VMware ESX Server 3, while the XenSource XenEnterprise platform on Linux offers paravirtualisation features.
• Type 2 hypervisor:The virtualisation software runs as another application within a standard OS. A prominent type 2 hypervisor for server virtualisation is Microsoft Virtual Server 2005 Release 2 (R2), which runs on top of the Microsoft Windows Server 2003 OS and uses hardware emulation virtualisation.
The lineage of x86 virtualisation goes back through VMware Workstation and VMware Server (formerly VMware GSX Server); this workstation virtualisation software was an early example of a type 2 hypervisor. VMware workstation software gave early adopters a practical way to virtualise their desktop systems, and set in motion a rapid progression of virtualisation technology.
But it was not until the advent of VMware ESX Server - a dedicated type 1 virtualisation platform that evolved from a Linux kernel - that server virtualisation and the concept of VMs began to make definitive strides into the mainstream.
Hypervisor technology, such as that included in VMware Infrastructure 3, has advanced to the point where it can begin to deliver on the promise of virtualisation by enabling highly efficient, automated resource sharing.
A centralised VMware VirtualCenter Management Server console helps ensure that systems throughout the enterprise data centre have the necessary computing muscle and I/O bandwidth when they need it, while features such as VMware Distributed Resource Scheduler (DRS) and VMware VMotion technology help distribute resources and move VMs efficiently across physical hosts.
As virtualisation continues to evolve, the role of the hypervisor is expected to mature to a higher level of standardisation than it has right now, particularly at the VM management level.
Today, virtualisation techniques have become key to building a cost-effective, highly scalable enterprise IT infrastructure, because they enable flexible resource management and automated resource allocation based on strategic business policies. Virtualisation technology can benefit the bottom line in several important ways:
• Implementing production server consolidation and containment:
Virtualisation techniques help contain server sprawl by running software applications in easily relocatable VMs on highly scalable enterprise-class servers. For example, VMware Infrastructure 3 enables the consolidation of numerous VMs on each physical server, which can lead to dramatic increases in server utilisation. Additionally, Microsoft Virtual Server and Xen virtualisation on Linux offer alternative platforms for virtualisation.
• Providing cost-effective protection for business continuity:Organisations can help ensure high availability for critical applications using industry-standard virtualisation-based solutions. This approach also enables organisations to implement a unified disaster recovery platform that allows them to recover many production VMs in the event of a hardware failure without investing in costly one-to-one mapping of production and disaster recovery hardware.
• Streamlining software testing and development:Virtualisation allows organisations to consolidate disparate test, development, and staging environments involving multiple operating systems and multi-tier applications on the same hardware. IT departments can also set up self-service developer portals to enhance developer productivity.
• Simplifying infrastructure provisioning:With sophisticated automation capabilities, organisations can provision new infrastructure components in minutes rather than the hours or days required for physical configurations. Virtualisation also allows IT organisations to centralise control and responsibility for hardware resources while giving business units and application owners control over how those resources are utilised.
• Re-hosting legacy applications:IT departments can migrate legacy operating systems and software applications to VMs running on upgraded hardware for enhanced reliability and resource management.
Today, virtualisation is cost-effective and easy to implement.
For many organisations, virtualisation is expected to be the most significant factor shaping IT infrastructure and operations. Moving forward, virtualisation will likely bring about fundamental changes in the way enterprises deploy and manage technology from the end user all the way to the data centre - including, for example, how they plan, what they buy, how they deploy new systems, how they account for usage and charge-backs, and how licensing, pricing, and component management work.
Storage has already been largely virtualised, but primarily within the scope of individual vendor architectures. Networking is already virtualised.
As virtualisation techniques and technologies continue to mature, the next major advancements will likely be automating the provisioning and management of virtualised server, storage, and networking resources.
Unlocking the business value of virtualisation
Virtualisation is now an industry-standard approach to data consolidation, which makes virtualisation key to a highly scalable, highly available enterprise IT infrastructure. A virtual infrastructure can help simplify IT operations in several important ways. For example, virtualisation helps shield software from hardware variability, enables secure resource sharing, and facilitates rapid software deployment and relocation.
Virtualisation also helps increase business agility by dynamically deploying or re-provisioning resources as needed. Advanced management tools such as VMware VirtualCenter together with shared storage can further optimise performance to help meet rigorous service-level agreements, avoid unplanned downtime, enhance the efficiency of application testing and development, and facilitate fast, cost-effective disaster recovery.
Because virtualisation enables multiple applications to share physical hardware, it allows organisations to lower requirements for data centre real estate, power consumption, and the volume of server hardware to be purchased and managed compared with non-virtualised configurations.
Virtualisation can also help reduce capital and operating expenses by creating an abstraction layer between the hardware and software stack that encapsulates the software workload in a VM.
This approach helps simplify the processes of moving workloads across hardware platforms, provisioning new servers, and supporting legacy applications on updated hardware.
Server virtualisation has entered the mainstream and is fast becoming an indispensable data centre technology.
Today, virtualisation is cost-effective and easy to implement even for small and midsize enterprises, helping expedite software deployment, accelerate disaster recovery, and dampen the impact of skyrocketing energy costs through consolidation to powerful, energy-efficient servers.
As virtualisation techniques and technologies mature, the next major advancements are likely to be increasingly automated provisioning and management of virtualised server, storage, and networking resources - including variable usage accounting and charge-backs.
It will likely not be long before virtualisation extends past servers to the desktop.
With a virtual desktop - a server-hosted approach to client virtualisation designed to deliver desktop images to end users through a remote protocol - even highly mobile users would be able to access their own desktop anywhere, from any device.
Moving forward, virtualisation is expected to be a significant factor shaping IT infrastructure and enterprise-wide business operations from the data centre to the desktop and beyond.
In many organisations, the bottom line is already profiting from reduced IT infrastructure costs, simplified management, and unprecedented business response.
Edited with permission from Dell Power Solutions magazine, August 2007. Copyright © 2007 Dell Inc. All rights reserved. Dell virtualization solutions: www.dell.com/virtualization. Dell Virtualization Services: www.dell.com/virtualizationservices.