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.
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.

VMware's headquarters at 3401 Hillview
Avenue in Palo Alto, California
See also
References
- VMware Converter. Retrieved 2008-03-31.
External links