VMware
From Wikipedia, the free encyclopedia
| VMware Inc. | |
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| Type | Public (NYSE: VMW) |
| Founded | California, 1998 |
| Headquarters |  Palo Alto, California, USA |
| Key people | Diane Greene Mendel Rosenblum |
| Industry | Computer software |
| Products | VMware ESX Server VMware Workstation VMware Fusion VMware Player VMware Server Virtual Infrastructure VMware ACE VMware Lab Manager VMware Converter |
| Revenue | US $ 1.33 Billion |
| Employees | 7,500 |
| Parent | EMC Corporation |
| Website | www.vmware.com |
VMware, Inc. (NYSE: VMW) is a software developer and a global leader in the virtualization market. The company was founded in 1998 and is based in Palo Alto, California. The name "VMware" comes from the acronym "VM", meaning "virtual machine", while ware comes from second part of "software".
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.
On 2007-08-14, 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.[1]
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[edit] 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 systems 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 area network (SAN).
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 virtualization does not replace offending instructions, and does not simply run kernel-code in user-mode. Both of these approaches run into difficulties on x86-based platforms. 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 drivers 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.
[edit] Products
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For more details on this topic, see List of VMware software.
[edit] Desktop software
VMware launched its first product, VMware Workstation, 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 MacIntel platform, along with full compatibility with virtual machines created by other VMware products.
For users without a license to use VMware Workstation or VMware Fusion, VMware offers the freeware VMware Player product, which can run (but not create) virtual machines.
[edit] Server software
VMware markets two virtualization products for servers: VMware ESX Server (formerly called "ESX Server") and VMware Server (formerly called "GSX Server").
VMware ESX, an enterprise-level product, can deliver greater performance than the freeware VMware Server, due to lower system overhead. In addition, VMware ESX integrates into VMware Virtual Infrastructure, which offers extra services to enhance the reliability and manageability of a server deployment. The VMware Server product offers a user interface with a similar look-and-feel to VMware Workstation.
VMware Server is also provided as freeware, like VMware Player but it is possible to create virtual machines with it.
[edit] Other products
VMware Converter allows users to build virtual machines — compatible with VMware ESX Server, VMware Server and VMware Workstation — either from physical machines running Microsoft Windows[2] (XP or later) or from virtual machines made by other virtualization products. Converter replaces 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 is a virtualization suite capable of creating portable software ("portable apps")
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 folders, 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.[3]
VMware announced in September 11th at VMworld 2007 the release of large portions of VMware Tools for Linux, Solaris and FreeBSD guests under GPL and GPL-compatible licenses and the creation of the Open Virtual Machine Tools ("open-vm-tools") project on Sourceforge.net. [4]
[edit] History
Diane Greene, Mendel Rosenblum, Scott Devine, Edward Wang and Edouard Bugnion founded VMware in 1998.[5] Greene had earned a Master's Degree in Naval Architecture from MIT in 1978, and in 1988 she earned a second Master's Degree in Computer Science from the University of California at Berkeley.[6] Rosenblum and Greene first met while at Stanford.
[edit] Location
The company has its headquarters in Palo Alto, California, United States,[7] with additional offices located in Palo Alto and San Francisco, California; Broomfield, Colorado; Cambridge, Massachusetts;[8] London, UK; Aarhus, Denmark; Sofia, Bulgaria; Sydney/Melbourne/Brisbane/Canberra/Perth/Adelaide, Australia; Wellington/Auckland, New Zealand; Hong Kong; Beijing/Shanghai, China; Singapore; Kuala Lumpur, Malaysia; Taipei, Taiwan; Bangalore/Pune/New Delhi/Guindy/Mumbai, India; Seoul, Korea; Tokyo, Japan; Cork, Ireland and Toronto, Canada.
[edit] See also
[edit] References
- ^ Mullins, Robert (2007-08-14). Update: VMware the bright spot on a gray Wall Street day. IDG News Service. Retrieved on 2007-08-15.
- ^ VMware Converter, retrieved 2008-03-31
- ^ Installing and Upgrading VMware Tools. Workstation User’s Manual. VMware, Inc. (2007-09-20). Retrieved on 2007-11-02.
- ^ http://lxer.com/module/newswire/view/92570/index.html
- ^ VMware Leadership.
- ^ Lashinsky, Adam (2007-10-02). Full speed ahead. Fortune Magazine. Retrieved on 2007-10-04.
- ^ VMware Office Locations. VMware, Inc.. Retrieved on 2008-03-04.
- ^ VMware Office Locations - Massachusetts. VMware, Inc.. Retrieved on 2008-03-04.
[edit] External links
- VMware Inc. website
- VMware VMTN (VMware Technology Network) Discussion Forums
- VMware Virtual Appliances Marketplace directory
- VMware Academic White Papers
- VMware Newsgroups
- U.S. Patent 6,397,242 — VMware patent application, containing an extensive explanation of the technology.
