Related Products and Open Source Projects  661
 e core strength of the way that BOCHS has been developed is that it
has been written in C++. By doing this, Kevin Lawton, the original author of
BOCHS, laid down a great deal of portability.  ere is usually a price for por-
tability and this case is no exception. BOCHS does not provide a high-perfor-
mance platform, which does not make it a good candidate for the enterprise.
BOCHS delivers poor performance from nearly all aspects; however the fact that
it can run almost any x86 operating system may outweigh the poor performance
in certain situations.
Applications where BOCHS may be an excellent solution include support
of very old operating systems that require outdated legacy hardware or develop-
ment environments that are used for things such as hardware device driver de-
bugging, simulation of hardware or operating system development.  e ability
to add custom virtual hardware monitoring hooks into the source code is some-
thing that may be incredibly valuable. Another incredible feature is the ability to
simulate certain events, such as hardware faults occurring through custom code.
 is will provide information that would be very diffi cult and time consuming
if it was attempted with physical hardware.
All in all, BOCHS is a project to watch as it is being advanced daily and is
making considerable strides in adding additional functionality and options.
QEMU
 e QEMU ( project is an open source emu-
lator providing the ability to run on a wide variety of platforms by doing dy-
namic translation of native CPU instructions (see Figure 28.6).  e dynamic
translation enables QEMU to provide a fast and effi cient emulation by break-
ing down the processor instructions into small blocks of atomic instructions.
 ese instructions are then processed, cached in a buff er, and then the responses
returned as if the native processor had acted upon them.  is project may not
Figure 28.6
QEMU.
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662  Advanced Server Virtualization
seem to fall into the virtualization camp; however there are two outside factors
that have been taken into consideration.
 e fi rst factor is that additional work has been done to speed up the per-
formance of QEMU in an attempt to match the speed and performance of sev-
eral of the commercial products available.  e heart of this project is called the
QEMU Accelerator Module and it is an additional virtualization layer.  is vir-
tualization layer provides a signifi cant performance increases and brings QEMU
into the fold as a player in the virtualization space.  is also shows that the
combination of technologies from several of these sources can provide comple-
mentary benefi ts if implemented properly.
 e second factor, which builds on the fi rst, is the fact that Win4Lin Pro also
leverages the same QEMU Accelerator Module that the QEMU project uses.
 is shows that even a thin virtualization layer can have multiple uses in the
commercial space. It is important to note that the QEMU Accelerator Module
is given away free to individuals, but is actually proprietary or closed source.
Developed by Fabrice Bellard in France, the author of QEMU, Bellard licensed
the QEMU Accelerator to Win4Lin and is at present willing to license the tech-
nology to other commercial entities based on negotiated terms.
 e QEMU Accelerator Module actually passes through many of the com-
mands that are normally dynamically translated.  is provides the same strength
and similar technical implementations to that of the VMware and Microsoft
virtualization solutions.  e weakness of this solution is the lack of support by
the commercial vendors and the mixed compatibility depending on what host
and guest operating system is used.
User-Mode Linux and VServer
User-Mode Linux () and VServer
() are more of isolation mechanisms than complete com-
puter isolation style virtualization.  ey simply off er a way to install and protect
several diff erent distribution instances of Linux from each other. Both provide

equivalent functionality and performance.  e advantage is packing on a great
deal of Linux installations onto a single server, which is incredibly advantageous
for entities such as hosting providers.  e disadvantages are primarily the in-
ability to run Microsoft Windows-based operating systems or other operating
systems not Linux-based. Another disadvantage is the requirement that all ver-
sions of Linux must support the native hardware confi guration and processor to
run and operate properly.
Xen
 e Xen ( project started
out at Cambridge University in the UK (see Figure 28.7). Xen is a hypervisor-
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Related Products and Open Source Projects  663
based technology, otherwise known as a Virtual Machine Monitor (VMM). Like
VMware’s ESX Server, Xen runs on the bare metal hardware with no supporting
operating system beneath it. Unlike VMware’s ESX Server however, Xen uses a
solution called paravirtualization.
Paravirtualization diff erentiates itself from standard virtualization in that in-
stead of adjusting the virtualization platform to support diff erent guest operating
systems and their behaviors (specifi cally the processor instructions they invoke),
the guest operating systems themselves are altered to support the virtualization
platform beneath them.  ere are several advantages to this approach; the fi rst is
the ability to get at or near physical hardware performance inside of the virtual
machines themselves.  e second is the rapid portability that this provides—
there are no special circumstances to deal with, all guests operate the same.  e
downside is also pretty signifi cant. Because of its need for changes to the guest
operating system, it can only support Linux and BSD variants at this time.  ere
are other ports taking place, however the major guest operating system, Micro-
soft Windows, cannot be altered in this fashion because it is closed source.
Xen is planning to off er many new capabilities in their new release includ-
ing full SMP support, live virtual machine migrations, scalability to 8TB of

memory, performance improvements, and support for more QoS (Quality of
Service) functions. Xen is poised to become a major player in the virtualiza-
tion space. To date Xen has been able to also leverage the work of several other
projects including BOCHS and QEMU. By leveraging these technologies, Xen
has been able to implement many performance optimizations already created by
these two projects.
Summary
 ere are many virtualization solutions available in both the commercial and
open source areas, however each has limitations. If consideration is being given
Figure 28.7 Xen.
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664  Advanced Server Virtualization
to one of these solutions over the two standards, VMware and Microsoft’s vir-
tualization solutions, then it is important to learn as much as possible through
thorough investigation, research, and testing, before making any decisions.  e
most promising solutions on the commercial side are Win4Lin and Virtual Iron,
however as of today, Virtual Iron VFe appears to be getting the most press al-
though it has not been released. Win4Lin Pro is released and has been around
for a while and is generally not well known.  e most promising solutions on
the open source side are BOCHS, QEMU, and Xen. Xen has a commercial as-
pect through a newly funded company named Xen Source that appears to have
a chance at doing for Xen what Red Hat has done for Linux.
All of these solutions are unsupported by Microsoft as of this time.  erefore
it is not recommended that any of these virtualization solutions listed above be
used for a production data center to run Microsoft Windows-based guest oper-
ating systems. Microsoft will generally not provide any support for its operating
systems running in these virtual machines unless the problem can be reproduced
on a physical server.
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665

Chapter 29
Other Virtualization
Resources
In addition to the products and projects described in chapter 28 and throughout
the book, there are also some third-party products and services, both large and
small, available to address niche areas of server virtualization.  is chapter pro-
vides a brief look at the resources provided by the major virtualization vendors
along with other resources being made available through the Internet that deal
with virtualization in one form or another.
Product Vendor Resources
Microsoft
/> e Microsoft Virtual Server 2005 R2 Web page provides some of the most
up-to-date information on the product (see Figure 29.1). It off ers a number of
relevant technical links along with links to numerous resource fi les. Microsoft
provides many diff erent ways to research and fi nd answers to Microsoft Virtual
Server 2005 R2 technical questions. Newsgroup support, a listing of the most
frequently asked questions (FAQs), a number of product and technical white
papers on the product, Web casts, online documentation and downloads that
include product updates and add-on software are also provided.
 ere are also several other valuable links created from Microsoft insiders
on their own personal blogs.  ese blogs represent a rich source of technical
information around Virtual Server. It should be noted that this resource is not
offi cially sanctioned by Microsoft. Many of these blog links can be found at
o/links.
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666  Advanced Server Virtualization
VMware
/> e VMware Web site provides a tremendous amount of resources relating to
the various product off erings made by VMware (see Figure 29.2).  ey off er
news and events that customers of their products will more than likely be inter-

ested in hearing about.  ey also off er the latest updates and security patches
for all of their products in a download section. But perhaps the most important
area on VMware’s Web site is the VMware Technology Network (VMTN) page.
 is technical and community resource page provides links to documentation,
FAQs, technical resources in the form of news and white papers, and developer
resources in the form of code and SDK packages. VMware is also a big propo-
nent for information sharing.  e VMTN page provides for a searchable knowl-
edge base as well as a discussion forum where users are able to post questions
and receive answers from other users as well as from VMware employees.  is
resource is probably the most likely place to fi nd answers to VMware product
questions. Unfortunately, there can also be erroneous information posted by
end users that must be waded through in order to fi nd the correct answer to the
question.
Figure 29.1 Microsoft.
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Other Virtualization Resources  667
Xen
/>Xen is an open-source virtualization project that was created at the University of
Cambridge.  e Cambridge Web site makes a number of resources available for
the product (see Figure 29.3). It off ers the standard documentation and FAQ’s
for the product, along with source code, and papers and presentations describ-
ing Xen’s design and architecture. Because the project is open-source, there are
already numerous user-owned Web sites covering the product and the support
Figure 29.2 VMware.
Figure 29.3 Xen.
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668  Advanced Server Virtualization
community is quickly growing with the incorporation of Xen’s paravirtualization
technology into Red Hat Linux, SUSE, and other operating system vendors’
technology stacks. A simple Google of “Xen virtualization” will unveil a plethora

of information and resources covering the product. For an in-depth listing of
links and resources related to Xen, visit o/links.
Computer Associates
/>Computer Associates off ers virtualization integration into their Unicenter Net-
work and Systems Management (Unicenter NSM) package (see Figure 29.4).
Unicenter NSM can now monitor the health and availability of virtual machines
running on VMware and Microsoft Virtual Server 2005.  e product also pro-
vides such features as policy-based automation, root-cause analysis, reporting,
and role-specifi c visualization.  is software tool would appeal to current users
of the Unicenter operations management software that are currently looking to
implement server virtualization into their organization.
Dunes
/>Dunes enables IT personnel to perform what they do best by capturing and
automating repetitive, tedious, and error-prone tasks.  e software solution
they provide off ers a graphical interface used to program various operations into
a virtual infrastructure (see Figure 29.5). Dunes Virtual Service Orchestrator
(Dunes VS-O) is a virtual server software solution for VMware VirtualCen-
ter and Microsoft Virtual Server 2005. Dunes VS-O is about capturing best
practices and business policies to help make the data center more effi cient and
adaptive to changing business practices. By utilizing one of their other products,
Dunes VS-M, a Microsoft Virtual Server environment can be centrally managed
from a single console. Dunes VS-M gives a logical representation of the entire
Figure 29.4 Computer
Associates.
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Other Virtualization Resources  669
Microsoft Virtual Server infrastructure.  e product is easily deployed without
the need for agents being required on the host servers. Both products are avail-
able for installation on a Windows operating system.
IBM

/>IBM is off ering several solutions around virtualization including the IBM Vir-
tual Machine Manager and the IBM Virtualization Engine Suite (see Figure
29.6).  e IBM Virtual Machine Manager (VMM) is an extension to IBM
Director that provides management of both physical and virtual machines all
from a single console. VMM allows for the management of both VMware ESX
Server and Microsoft Virtual Server 2005 environments using IBM Director.
To create an even more advanced virtual machine management environment,
VMM can also integrate VMware VirtualCenter with IBM Director. Another
product off ering, the IBM Virtualization Engine, enables individual distributed
resources across the enterprise to function cohesively as a single pool or entity.
 e product allows for greater effi ciency when accessing and managing resourc-
es across the organization. IBM is clearly hedging its bets by diversifying and
spreading their risk across multiple technologies.  ey have strategically aligned
themselves with most of the major virtualization platform vendors, including:
Figure 29.5 Dunes.
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670  Advanced Server Virtualization
Microsoft, VMware, and Xen. IBM is still one of the few companies around that
off ers a complete virtualization solution including hardware (server and storage),
software, and services.
Leostream
/>Leostream is a vendor agnostic virtualization management software company
(see Figure 29.7). Leostream’s Virtual Host Desktop Controller is a manage-
ment product that attempts to solve a wide range of problems facing today’s data
centers: quality assurance, support, server consolidation, and disaster recovery. It
contains features such as: performance monitoring and reporting, policy-based
access control, fail-over for virtual and physical machines, and disaster recovery.
 e product manages virtual servers running under VMware ESX Server, VM-
ware GSX Server for Windows, and Microsoft Virtual Server 2005 and is also
compatible with VMware VirtualCenter. Additionally, Leostream off ers its own

version of P2V aptly named P>V Direct 2.0. Its claim to fame is the ability to
perform a conversion directly from a running Windows server to a virtual server
without the need for a CD, fl oppy disk, or a reboot. Its biggest drawback—it
Figure 29.6 IBM.
Figure 29.7 Leostream.
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Other Virtualization Resources  671
can only convert Microsoft Windows operating systems so there is no support
for Linux.
Platespin
/>Platespin currently has several virtualization products on the market that at-
tempt to bring optimization to the IT industry and help to bring automation
to the data center (see Figure 29.8). PowerConvert is a utility that attempts to
provide 100 percent automated conversions between physical and virtual ma-
chines running either a Windows or Linux operating system.  ey also off er the
Platespin Operations Management Center, a comprehensive physical and virtual
server management solution.  e product off ers automated discovery, provi-
sioning, management, and monitoring all from a single console. To help round
out their product off ering, they present the PowerRecon product, a resource
measurement, data collection, and analysis tool designed to help a data center
plan for server consolidation projects. According to Platespin, there have already
been over 600 companies that have used their PowerConvert product.  is is
signifi cant in that it not only shows that the product has gained traction in the
marketplace and has matured rapidly, but that the marketplace is also quickly
adopting virtualization as a platform.
Surgient
/>As an early adopter of server virtualization, Surgient was a pioneering company
becoming one of, if not, the fi rst companies to leverage virtualization as an API
Figure 29.8 Platespin.
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672  Advanced Server Virtualization
platform for a software solution (see Figure 29.9). Surgient provides on-demand
applications that enable companies to increase the eff ectiveness of their direct
sales, online marketing, technical training, and QA/Verifi cation processes. Sur-
gient has created its own virtualization vendor agnostic management interface
that not only provides a comprehensive management solution, but when pack-
aged with its application off erings, it enables the use of distributed enterprise
application environments by any user, on-demand, from anywhere at anytime.
It eliminates the complexities of hardware confi guration and software environ-
ment provisioning. Surgient is able to off er its products to its customers in the
form of a hosted solution as well as a licensed package.
Resources and Web Links
About Virtualization
/>Similar to Virtualization.info, this Web site attempts to cover all the latest news
and information about virtualization (see Figure 29.10).  e Web site provides
an easy to read layout covering its news articles, and it also provides a number
of links to items such as: white papers, interviews, product updates and patches,
slide shows, and tools and utilities. A user forum is also provided using the
popular phpBB software. Bloggers with virtualization knowledge and experience
are welcomed to apply to provide content to the site.
Figure 29.9 Surgient.
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Other Virtualization Resources  673
ExtremeVM.com
/>Founded in 2004 and offi cially launched in 2006, ExtremeVM.com is a com-
munity-oriented virtualization magazine created by virtualization enthusiasts
for virtualization enthusiasts (see Figure 29.11). It sports a clean, easy-to-read
design and off ers articles, aggregated virtualization industry news, and commu-
nity resources. It is an online-only magazine focused on fostering community
involvement in the development of new ideas, uses, and applications for all vir-

tualization technologies, including application virtualization, desktop virtualiza-
tion, network virtualization, server virtualization, storage virtualization.
The MiniMe Project
/> is ambitious project is currently downloadable as a Beta release (see Figure
29.12).  e project’s goal is to provide a windows GUI management console
that allows the management of VMware ESX, GSX and Microsoft Virtual Serv-
er through a single unifi ed interface.  e project is attempting to provide more
sophistication than just a simple management interface. A current list of features
includes: hot backup and restore, standby clustering, dynamic REDO creation,
Figure 29.10 About Virtualization.
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674  Advanced Server Virtualization
Figure 29.11 ExtremeVM.com.
detailed guest confi guration, and support for various authentication services
such as LDAP, Active Directory, and SMB.  e author is currently accepting
feature requests and comments about the project.
Virtualization.info
o/
 is blog site is a great place to obtain aggregated news on virtualization (see
Figure 29.13). It off ers a very nice design that is easy-to-read and has a pleas-
ant look-and-feel that is more unique than typical blog sites. To its credit, the
site also off ers numerous links to other Web sites, blogs and wikis that also off er
news and information that pertains to virtualization.  e Web site is presently
operated by its creator, Alessandro Perilli.
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Other Virtualization Resources  675
Figure 29.12 The MiniMe Project.
Figure 29.13 Virtualization.info.
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676  Advanced Server Virtualization

Virtual Strategy Magazine
/> is is an online-only technical and news magazine that provides its readers with
news and technical information that focuses solely on virtualization (see Figure
29.14). In addition to providing news, the magazine also provides technical tips,
real-world experiences from virtualization users, and interviews with many key
individuals in the virtualization fi eld. For members of the Web site, free telecon-
ferences and Web seminars are occasionally off ered.
VMbook.info
o/
VMbook.info is the offi cial Web site supporting this book, Advanced Server
Virtualization, VMware and Microsoft Platforms in the Virtual Data Center.
Any errata, additional supporting materials, and resources for this book will be
posted on the Web site.  e Web site can also be used to contact the authors, if
necessary, and provide any direct feedback.
VMware’s Back

 is Web site is operated by Ken Kato and provides a set of tools that Kato him-
self has written (see Figure 29.15). Two of the more popular downloads include
Figure 29.14 Virtual Strategy
Magazine.
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Other Virtualization Resources  677
the Virtual Disk Driver and the Virtual Floppy Driver.  e Virtual Disk Driver
allows many versions of VMware’s virtual disk fi les to be mounted to a Win-
dows host machine and then used as a read-only or read-write disk drive.  e
Virtual Floppy Driver is a similar product, allowing a virtual fl oppy image to
be mounted to a Windows host machine and used as a virtual fl oppy drive.  e
contents of which can be accessed directly by either viewing, editing, renaming,
deleting, or creating fi les on a virtual fl oppy disk much like a real physical fl oppy
disk.  e site is available in both English and Japanese, and now off ers a user

forum powered by phpBB.
Summary
Server virtualization as a platform is starting to take hold and spread throughout
the IT community. Its popularity and usefulness is evidenced by the numerous
third-party software packages that are being developed, sold, and downloaded in
addition to all of the news and information Web sites that are starting to appear
across the Internet.  e resources discussed in this chapter are but a brief look
at the many informational Web sites, and commercial and public projects and
products being off ered to help fully utilize and understand server virtualization.
 ese are only a select few of the server virtualization resources that are currently
available and the list is continuously growing. Please visit ook.
info/ (see above) for a more complete and current list of available resources and
links.
Figure 29.15 VMware’s Back.
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Part VIII
Appendices
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681
Appendix I
Deployment Planning
Checklist
Use Case(s)


Planning and Technical Teams Identifi ed



Problem Outlined and Detailed


Solution Outlined and Detailed


Use Case Document Created Including:


Change Cause and Outcome


Change Impact to Systems


Change Impact to Processes and Job Functions


Business Constraints


Technical Constraints
Requirements


Defi ned Constraints


Project Limitations



Time Limitations


Scope Changes


Inclusion of Use Case(s)
Deployment Plan


Server Virtualization Platform Selected


Hardware Compatibility


Host Operating System Support


Guest Operating System Support


Application Support


Capacity and Scalability


Features, Manageability

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682  Advanced Server Virtualization


Performance


Support, Maintenance, Training


Cost
Hardware


CPU Capacity/Performance Limitations


Memory Limitations


Network Limitations


Compatibility


Cost
Software Licenses



In Compliance
Solution


Vendor Support


Scalability


Redundancy, Backup Time and Availability


Disaster Recovery


Monitoring


Networking


Performance


Security
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683
Appendix II
File Extensions by

Virtualization Platform
Virtual machines are typically stored on a host server and are made up of a set of
fi les that are typically located in a directory created for the virtual machine.  is
chapter provides a simple view of commonly used fi le extensions sorted by server
virtualization platform and a short description of each (see Figure 31.1).
Microsoft Virtual Server
 VHD
 e .vhd fi le is the virtual machine’s disk fi le, which stores the contents of
the virtual machine’s hard disk.  ere are a number of ways this fi le can be
implemented.
• Fixed size disk
 e .vhd fi le is pre-allocated when the virtual hard disk is created.  e
host server must have enough free disk space to accommodate the size
of the fi le. A fi xed size disk cannot be resized.
• Dynamically expanding disk
 e virtual hard disk is created as a sparse fi le and the .vhd fi le grows
as the virtual machine adds data to the virtual disk. Virtual Server will
send a warning if the virtual disk grows too large for the host fi le sys-
tem.
• Diff erencing disk
A diff erencing disk sets up a parent and child relationship between vir-
tual hard disk fi les.  e diff erencing disk acts as the child, while the
associated virtual disk acts as the parent. While the diff erencing disks
created on the host machine may contain multiple fi les, they will appear
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684  Advanced Server Virtualization
to the guest server as a single hard disk. While the virtual machine is in
use, it will read from both, the parent and the child disk fi les. However,
any changes or writes that occur will be written against and updated
into the child disk fi le only.

 VMC
 e .vmc fi le is an XML fi le that stores metadata describing the virtual
machine’s confi guration information.  e fi le is created when a new vir-
tual machine is created, and it contains the settings that make up the vir-
tual machine.  e contents can be modifi ed by using the virtual machine
settings editor or by using any third-party text editor.
 VUD
 e undo disk fi le is created automatically when a virtual machine con-
fi gured with Undo Disks is powered on. When this feature is enabled, it
universally applies to all virtual hard disks that are attached to the virtual
machine. While the virtual machine is running, any changes made to the
virtual disk are written to the .vud fi le; reads occur from the original virtual
hard disk.
 VSV
 e .vsv fi le is created automatically when a virtual machine is suspended.
 e fi le contains the entire state of the virtual machine. Once suspended,
the virtual machine is in a hibernation state, similar to that of a laptop
computer.  e .vsv fi le is then used to resume the virtual machine from the
suspended state.
Virtualization Platforms
ESX GSX MSVS
File Types
Disk File DSK, VMDK PLN, DAT, DSK, VMDK VHD
Config File CFG, VMX CFG, VMX VMC
Undo Disk REDO REDO VUD
Suspended State VMSS VMSS, STD VSV
Log Files LOG LOG TXT
Floppy Disk FLP FLP VFD
CDROM Image ISO ISO ISO
Network Configuration N/A N/A VNC

CMOS/BIOS NVRAM NVRAM -
Snapshot N/A VMSN N/A
* ESX = VMware ESX Server, GSX = VMware GSX Server, MSVS = Microsoft Virtual Server
Figure 31.1 File Extensions At-A-Glance.
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File Extensions by Virtualization Platform  685
 VNC
 e .vnc fi le is an XML fi le that stores metadata describing the virtual
machine’s network confi guration information. When a virtual network
is created, a virtual network confi guration fi le is created and by default
placed in the
C:\Documents and Settings\All Users\Docu-
ments\Shared Virtual Networks
directory.
 TXT
Virtual Server log fi les are stored in .txt fi les. An important log fi le to re-
member is the VSCrashLog text fi le. It is created when a virtual machine
stops responding. When calling for support, Microsoft may request this
fi le to help troubleshoot the problem.
 VFD
 e .vfd fi le is used to store content in the form of a virtual fl oppy disk.
Virtual Server can mount most fl at-fi le representations of a fl oppy disk,
including fl oppy disks that are 720 KB or 1.44 MB in size.
 ISO
 e .iso fi le is used to store content in the form of a virtual CD/DVD-
ROM. An .iso fi le can be downloaded from the Internet or created with
ISO imaging tools as described in chapter 27.
VMware ESX Server
 DSK
 e .dsk fi le is a legacy virtual machine disk fi le. Earlier versions of the

VMware ESX product used the .dsk extension, however, to gain cross plat-
form parity, VMware ESX has moved to the .vmdk format.
 VMDK
 e .vmdk fi le is the virtual machine’s disk fi le, which stores the contents
of the virtual machine’s hard disk. VMware ESX disk fi les are fi xed in size,
meaning it is pre-allocated to the full specifi ed disk size when the fi le is
created.
 CFG
 e .cfg fi le is a legacy virtual machine confi guration fi le created with ver-
sions of VMware ESX Server prior to the 2.0 release. Virtual machine con-
fi guration fi les with a .cfg extension can still be accessed by ESX versions
2.0 and later.
 VMX
 e .vmx fi le is used to store virtual machine confi guration information.
 is fi le is created when a new virtual machine is created, and it contains
the settings that make up the virtual machine.  e contents can be modi-
fi ed by using the virtual machine settings editor or by using any third-
party text editor.
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