VMware, Inc. ( ) is the leading provider of virtualization software. The company was founded in 1998 and is based in Palo Alto, California. The Company is majority owned by EMC Corporation (NYSE: EMC).

VMware's desktop software runs on Microsoft Windows, Linux, and Mac OS X. VMware's enterprise software, VMware ESX Server, runs directly on server hardware without requiring an additional underlying operating system.

History

In 1998, VMware was founded by Diane Greene, Mendel Rosenblum, Scott Devine, Edward Wang, and Edouard Bugnion. Rosenblum and Greene, who are married, first met while at Berkeley. Edouard Bugnion remained the chief architect and CTO of VMware until 2005, and went on to found Nuova Systems (now part of Cisco).

The company has its headquarters in Palo Alto, California, United States, and established an R&D Center in Cambridge, Massachusetts, as well as one at the Time Warner Center in New York City, in 2005. VMware software runs on Windows and on Linux, and made its debut on Mac OS X in December, 2006. Their customers include all 100 of the Fortune 100 companies .

VMware delivered its first product, VMware Workstation, in 1999 and entered the server market in 2001 with VMware GSX Server (hosted) and VMware ESX Server (hostless).In 2003 VMware launched VMware Virtual Center, the VMotion and Virtual SMP technology. 64-bit support appeared in 2004. The company was also acquired by EMC Corporation that same year.

In August 2007, EMC Corporation released 10% of the company's shares in VMware in an initial public offering on the New York Stock Exchange. The stock debuted at 29 USD per share and closed the day at 51 USD.

On July 8, 2008, VMware co-founder, president and CEO Diane Greene was unexpectedly fired by the VMware Board of Directors and replaced by Paul Maritz, a retired 14-year Microsoft veteran who was heading EMC's cloud computing business unit. In the same news release VMware stated that 2008 revenue growth will be "modestly below the previous guidance of 50% growth over 2007." As a result, market price of VMware dropped nearly 25%. Then on September 10, 2008, Rosenblum, the company's chief scientist, resigned from VMware.

On September 16, 2008, VMware announced that they are collaborating with Cisco to provide joint data center solutions. One of the first results of this is the Cisco Nexus 1000V, a distributed virtual software switch that will be an integrated option in the VMware infrastructure.

VMware acquired Tungsten Graphics, a company with core expertise in 3D graphics driver development on November 26, 2008.

On August 10, 2009, VMware announced the acquisition of SpringSource, a leader in enterprise and web application development and management.

Core product design

VMware software provides a completely virtualized set of hardware to the guest operating system. VMware software virtualizes the hardware for a video adapter, a network adapter, and hard disk adapters. The host provides pass-through drivers for guest USB, serial, and parallel devices. In this way, VMware virtual machines become highly portable between computers, because every host looks nearly identical to the guest. In practice, a system administrator can pause operations on a virtual machine guest, move or copy that guest to another physical computer, and there resume execution exactly at the point of suspension. Alternately, for enterprise servers, a feature called VMotion allows the migration of operational guest virtual machines between similar but separate hardware hosts sharing the same storage. Each of these transitions is completely transparent to any users on the virtual machine at the time it is being migrated.

VMware Workstation, Server, and ESX take a more optimized path to running target operating systems on the host than emulators (such as Bochs) which simulate the function of each CPU instruction on the target machine one-by-one, or dynamic recompilation which compiles blocks of machine-instructions the first time they execute, and then uses the translated code directly when the code runs subsequently. (Microsoft Virtual PC for Mac OS X takes this approach.) VMware software does not emulate an instruction set for different hardware not physically present. This significantly boosts performance, but can cause problems when moving virtual machine guests between hardware hosts using different instruction-sets (such as found in 64-bit Intel and AMD CPUs), or between hardware hosts with a differing number of CPUs. Stopping the virtual-machine guest before moving it to a different CPU type generally causes no issues.

VMware's products use the CPU to run code directly whenever possible (as, for example, when running user-mode and virtual 8086 mode code on x86). When direct execution cannot operate, such as with kernel-level and real-mode code, VMware products re-write the code dynamically, a process VMware calls "binary translation" or BT. The translated code gets stored in spare memory, typically at the end of the address space, which segmentation mechanisms can protect and make invisible. For these reasons, VMware operates dramatically faster than emulators, running at more than 80% of the speed that the virtual guest operating-system would run directly on the same hardware. VMware claims an overhead as small as 3% to 6% for computationally-intensive applications.

VMware's approach avoids some of the difficulties of virtualization on x86-based platforms. Virtual machines may deal with offending instructions by replacing them, or by simply running kernel-code in user-mode. Replacing instructions runs the risk that the code may fail to find the expected content if it reads itself; one cannot protect code against reading while allowing normal execution, and replacing in-place becomes complicated. Running the code unmodified in user-mode will also fail, as most instructions which just read the machine-state do not cause an exception and will betray the real state of the program, and certain instructions silently change behavior in user-mode. One must always rewrite; performing a simulation of the current program counter in the original location when necessary and (notably) remapping hardware code breakpoints.

Although VMware virtual machines run in user-mode, VMware Workstation itself requires the installation of various driver in the host operating-system, notably to dynamically switch the GDT and the IDT tables.

The VMware product line can also run different operating systems on a dual-boot system simultaneously by booting one partition natively while using the other as a guest within VMware Workstation.

Products

Desktop software

• VMware Workstation (first product launched by VMware in 1999). This software suite allows users to run multiple instances of x86 or x86-64 -compatible operating systems on a single physical PC.
• VMware Fusion provides similar functionality for users of the Intel Mac platform, along with full compatibility with virtual machines created by other VMware products.
• VMware Player For users without a license to use VMware Workstation or VMware Fusion, VMware offers this software as freeware product for personal use. While initially not able to create virtual machines, this limitation was removed in version 3.0.

Server software

VMware markets two virtualization products for server:

• VMware ESX (formerly called "ESX Server"), an enterprise-level product, can deliver greater performance than the freeware VMware Server, due to lower system overhead. VMware ESX is a "bare-metal" product, running directly on the server hardware, allowing virtual servers to also use hardware more or less directly. In addition, VMware ESX integrates into VMware vCenter, which offers extra services to enhance the reliability and manageability of a server deployment, such as
  • VMotion - the capability to move a running virtual machine from one ESX host to another and faster than some other editions
  • Storage VMotion - the capability to move a running virtual machine from one storage device to another
  • DRS - Dynamic Resource Scheduler - automatic load balancing of a ESX cluster using VMotion
  • HA - High Availability - In case of hardware failure in a cluster, the virtual servers will automatically restart on another host in the cluster

VMware ESX Server is virtual infrastructure software for partitioning, consolidating and managing servers in mission-critical environments. Ideally suited for enterprise data centers, ESX Server minimizes the total cost of ownership of computing infrastructure by increasing resource utilization and its hardware-independent virtual machines encapsulated in easy to-manage files maximize administration flexibility.

• VMware ESXi (formerly called "VMware ESX 3i"), is quite similar to ESX, but differentiates in that the Service Console is removed, and replaced with a minimal BusyBox installation. Disk space requirements are much lower than for ESX and the memory footprint is reduced. ESXi is intended to be run from flash disks in servers but can be run from normal disks. VMware ESXi hosts can't be managed directly from the console, all management is performed through a VirtualCenter Server. In July 2008, VMware decided to give ESXi away for free.

• VMware Server (formerly called "GSX Server") is also provided as freeware, like VMware Player, but it is possible to create virtual machines with it. It is a "hosted" application, which runs within an existing Linux or Windows operating system.

Other products

VMware vCenter Converter (VMware Converter) comes in both Server and Standalone versions and is designed primarily for the following tasks:

• Convert a physical machine into a virtual machine; referred to as Physical-to-Virtual or P2V.
• Convert a virtual machine of one type into another.
• Run automated configuration tasks on VMware ESX/ESXi servers.

Converted VMs are compatible with VMware ESX/ESXi Server, VMware Server and VMware Workstation. A P2V conversion can be done from any physical machine running Microsoft Windows (XP or later) or Linux based (Linux only works on Standalone version). Conversions are managed from a centralized console allowing for multiple conversions at the same time. VMware vCenter Converter the older VMware products "P2V Assistant" and "Importer". P2V Assistant allowed users to convert physical machines into virtual machines; and Importer allowed the import of virtual machines from other products into VMware Workstation.

VMware Capacity Planner, an information technology (IT) capacity planning tool, collects utilization-data in heterogeneous computing environments and compares it to industry-standard reference-data to provide analysis and decision-support modeling.

VMware ACE provides a means of distributing secured virtual desktops to networked client PCs.

VMware ThinApp, formerly Thinstall, is a virtualization suite capable of creating portable software ("portable apps"). This software enables applications to execute without being previously installed.

VMware Infrastructure is a collection of VMware products used to manage a VMware ESX/ESXi server environment.

VMware vSphere is a "cloud OS". VMware vSphere 4 was originally named VMware Virtual Infrastructure (VI) 4 and is capable of managing large pools of infrastructure, including software and hardware both from internal and external networks.

The VMware Tools package adds drivers and utilities to improve the graphical performance for different guest operating systems, including mouse tracking. The package also enables some integration between the guest and host systems, including shared folder, plug-and-play devices, clock synchronisation, and cutting-and-pasting across environments. VMware Inc makes VMware Tools available for Microsoft Windows, Linux, Sun Solaris, FreeBSD, and Novell NetWare guest systems.

On September 11 at VMworld 2007, VMware announced that large portions of VMware Tools for Linux, Solaris, and FreeBSD guests were released under GPL and GPL-compatible licenses. They also announced the creation of the Open Virtual Machine Tools ("open-vm-tools") project on Sourceforge.net.

See also

• Comparison of platform virtual machines
• List of VMware software
• Virtualization
• VMware VMFS

References

1. VMware Converter. Retrieved 2008-03-31.

External links

• Company home page