Server Virtualization Software from VMware, Microsoft and XenSource

If you've got three single application servers supporting Accounts Payable and your data center struggles to maintain 84 degrees in the middle of January, it's time to consider virtualizing those servers. Sever virtualization allows you to merge several applications into one server, which saves money on hardware, real estate and energy.

Let's take a look at server consolidation software from the virtualization industry leaders: VMware's Server and Microsoft's Virtual Server.

VMware Server

From VMware: VMware Server installs on any existing server hardware and partitions a physical server into multiple virtual machines by abstracting processor, memory, storage and networking resources, giving you greater hardware utilization and flexibility. Streamline software development and testing and simplify server provisioning as you utilize the ability to "build once, deploy many times."

With this robust yet easy to use software you can:

  • Streamline software development and testing by allowing developers to create multiple environments with different operating systems on the same server.
  • Simplify IT testing of patches, new applications and operating systems by allowing systems administrators to test in secure virtual machines and be able to roll back to a clean state by leveraging snapshots.
  • Simplify server provisioning by building a virtual machine once and deploying it multiple times.
  • Evaluate software in ready-to-run virtual machines without installation and configuration.
  • Re-host legacy operating systems such as Windows NT Server 4.0 and Windows 2000 Server in a virtual machine running on new hardware and operating system.
  • Leverage pre-built, ready-to-run virtual appliances that include virtual hardware, operating system and application environments.

VMware Server is a free virtualization product for Windows and Linux servers with enterprise-class support and VirtualCenter management. VMware Server is a robust yet easy to use server virtualization product and is based on proven virtualization technology, which has been used by thousands of customers for more than six years. VMware Server:

  • Runs on any standard x86 hardware
  • Supports 64-bit guest operating systems, including Windows, Linux, and Solaris
  • Can be managed by VMware VirtualCenter to efficiently provision, monitor and manage infrastructure from a central management console
  • Supports two-processor Virtual SMP, enabling a single virtual machine to span multiple physical processors
  • Runs on a wider variety of Linux and Windows host and guest operating systems than any server virtualization product on the market
  • Captures entire state of a virtual machine and rolls back at any time with the click of a single button
  • Installs like an application, with quick and easy, wizard-driven installation
  • Quick and easy, wizard-driven virtual machine creation
  • Opens VMware or Microsoft virtual machine format and Symantec LiveState Recovery images with VM Importer
  • Supports Intel Virtualization Technology
  • Protects investment with an easy upgrade path to VMware Infrastructure

Microsoft Virtual Server

From Microsoft: In conjunction with Windows Server 2003, Virtual Server 2005 R2 SP1 provides a virtualization platform that runs most major x86 operating systems in a guest environment, and is supported by Microsoft as a host for Windows Server operating systems and Windows Server System applications. Virtual Server 2005 R2's comprehensive COM API, in combination with the Virtual Hard Drive (VHD) format and support for virtual networking, provide administrators complete scripted control of portable, connected virtual machines and enable easy automation of deployment, and ongoing change and configuration.

Additionally, its integration with a wide variety of existing Microsoft and third-party management tools allows administrators to seamlessly manage a Virtual Server 2005 R2 SP1 environment with their existing physical server management tools. A wide array of complementary product and service offerings are available from Microsoft and its partners to help businesses plan for, deploy, and manage Virtual Server 2005 R2 SP1 in their environment.

Virtual Server 2005 R2 SP1 Scenarios

Virtual Server 2005 R2 SP1 addresses four key customer scenarios:

  • Consolidate infrastructure, application, and branch office server workloads. Virtual Server 2005 R2 SP1 is ideal for server consolidation in both the datacenter and the branch office, allowing IT staff to make more efficient use of their hardware resources. It also allows IT staff to enhance their overall productivity and rapidly deploy new servers that enable the people in their organization to quickly address changing business needs.
  • Consolidate and re-host legacy applications. Virtual Server 2005 R2 SP1 enables re-hosting of legacy operating systems (Windows NT Server 4.0 and Windows 2000 Server) and their associated custom applications from older hardware to new hardware running Windows Server 2003.
  • Automate and consolidate software test and development environments. Virtual Server 2005 R2 SP1 enables IT and development staff to consolidate their test and development server farm and automate the provisioning of virtual machines.
  • Simplify disaster and recovery planning. Virtual Server 2005 R2 SP1 can be used as part of a disaster and recovery plan that requires application portability and flexibility across hardware platforms.

Xen Hypervisor

From XenSource: Enterprises are embracing Xen for server virtualization because it enables them to increase server utilization, consolidate servers, and dramatically reduce complexity and overall total cost of ownership. Xen is the fastest and most secure virtualization software available today, enabling every server to support multiple virtual servers each with resource guarantees to ensure that its application layer SLA is met.

Server Virtualization with the Xen Hypervisor

With Xen virtualization, a thin software layer known as the Xen hypervisor is inserted between the server's hardware and the operating system. This provides an abstraction layer that allows each physical server to run one or more “virtual servers,” effectively decoupling the operating system and its applications from the underlying physical server.

Once a virtual server image has been created it can run on any server, at any time, and multiple virtual servers can simultaneously share a single server, increasing its utilization while receiving a resource guarantee that ensures that application layer performance criteria are met.

Xen Is an Open Source Technology

The Xen hypervisor is a unique open source technology, developed collaboratively by the world's best engineers at over 20 of the most innovative data center solution vendors, including Intel, AMD, Cisco, Dell, Egenera, HP, IBM, Mellanox, Network Appliance, Novell, Red Hat, SGI, Sun, Unisys, Veritas, Voltaire, and of course, XenSource. Xen is licensed under the GNU General Public License (GPL2).

And best of all, as an open source technology, Xen is available free for download. XenSource also provides simple tools for the community to download, install, test and develop using Xen.

Xen enables IT managers to increase utilization of server resources, achieve server consolidation, scale their test & development environments, and achieve greater business continuity through dynamic provisioning. But to scale Xen deployments across the enterprise, users need a comprehensive tool set that enables them to deploy, control and monitor their Xen based data center.

Paravirtualization Provides Near-Native Performance

Xen's paravirtualization technology is widely acknowledged as the fastest and most secure virtualization software in the industry. Xen offers near-native performance for virtual servers with up to 10 times less overhead than proprietary offerings, and benchmarked overhead of well under 5% in most cases compared to 35% or higher overhead rates for other virtualization technologies.

With the 3.0 release, Xen extends its feature leadership with functionality required to virtualize the servers found in today's enterprise data centers. New features include:

  • Support for up to 32-way SMP guest
  • Intel® VT-x and AMD Pacifica hardware virtualization support
  • PAE support for 32 bit servers with over 4 GB memory
  • x86/64 support for both AMD64 and EM64T

Lean and Secure

Xen is exceptionally lean-- less than 50,000 lines of code. That translates to extremely low overhead and near-native performance for guests. Xen re-uses existing device drivers (both closed and open source) from Linux, making device management easy. Moreover Xen is robust to device driver failure and protects both guests and the hypervisor from faulty or malicious drivers.

Utility Based Computing

Xen is a key enabler in enterprises' aspirations towards a utility-based computing model, in which any server can run any operating system and any application, at any time, with dynamic load balancing of resources both within each server, between the guests, and across servers.

Per VM Resource Guarantees

Xen provides superb resource partitioning, for CPU, memory, and block and network I/O. This resource protection model leads to improved security because guests and drivers are DoS-proof. Xen is fully open to scrutiny by the security community and its security is continuously tested. Xen is also the foundation for a Multi-Level Secure system architecture being developed by XenSource, IBM and Intel.

An Emerging Open Industry Standard

Xen enjoys extraordinary community support. It is a de-facto, industry endorsed open source virtualization standard backed by the industry's leading enterprise solution vendors. Xen is, and always will be, open sourced, uniting the industry and the Xen ecosystem to speed the adoption of virtualization in the enterprise.