PARAVIRTUALIZATION
The main limitation of paravirtualization is the fact that the guest OS must be tailored specifically to run on top of the virtual machine monitor (VMM), the host program that allows a single computer to support multiple, identical execution environments. However, paravirtualization eliminates the need for the virtual machine to trap privileged instructions. Trapping, a means of handling unexpected or unallowable conditions, can be time-consuming and can adversely impact performance in systems that employ full virtualization.
Paravirtualization is an expansion of a technology that has existed for years in the IBM OS known as VM. Xen, an open-source software project, incorporates paravirtualization.
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HARDWARE EMULATION
A hardware emulator is designed to simulate the workings of an entirely different hardware platform than the one it runs on. Hardware emulation is generally used to debug and verify a system under design.
An administrator must use hardware emulation if he needs to run an unsupported operating system (OS) within a virtual machine (VM). In such a scenario, the virtual machine does not have direct access to server hardware. Instead, an emulation layer directs traffic between physical and virtual hardware. This is less efficient than paravirtualization, which allows for an interface to the virtual machine that can differ somewhat from that of the underlying hardware.
Microsoft's Hyper-V includes hardware emulation because the Integration Services can only be installed on certain guest operating systems. The hardware emulation allows the network administrator to run and interact with an embedded operating system from a desktop that couldn't normally support that operating system. (An embedded OS is a type of operating system that is created to run in dedicated hardware environments or on systems that aren't intended for interactive use.)
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SEVEN PERFECTLY LEGAL WAYS TO GETWINDOWS 7 CHEAP
Summary: You don't have to pay full price for
Windows 7. I've researched the best deals out
there, and can help you save 58%, 70%, 85%,
or even get Windowsp7 free. Keep reading.
By Ed Bott for The Ed Bott Report |
November 6, 2009 -- 06:21 GMT (22:21 PST)
Update, September 2, 2010: Several of the
deals listed in this post are no longer available.
For the latest on the Family Pack, be sure to
read this post: Windows 7 Family Pack
discounts return. And be sure to read this
follow-up post: Windows 7 deals: Harder to
find, but still there if you look.
Only suckers pay retail.
If you've read any reviews of Windows 7,
you've seen references to its price list, which
ranges from $120 for a Home Premium
upgrade to $320 for a fully licensed copy of
Windows 7 Ultimate.
Well, guess what? You don't have to pay that
much. Most people have much better options
available, if you know where to look. As I've
detailed here, the best deals go to PC
manufacturers, which you benefit from if you
buy a new PC.
But there are plenty of other discounts
available as well. In this post, I've researched
deals in three separate categories: upgrade
offers available to anyone, special deals just
for students, and subscriptions intended for
technical professionals and developers.
Most of the details I include here apply to
Windows customers in the United States, but
some offers are also available in other
countries. Where possible, I have tried to
track down those details and include the
names of countries where equivalent offers
exist. If you live outside the U.S., follow these
links to find prices and terms for your
country.
My goal in this post is to point you to deals
that customers legitimately qualify for. I am
not trying to encourage attempts by anyone to
get away with something you're not entitled to.
If there are restrictions for a specific offer,
I've noted them here.
[Update 6-Nov 1:00PM PST: Several people in
the comments have asked why I didn't
iunclude the Microsoft Action Pack in this
post. Two reasons: First, it is available only to
bona fide system builders, and that's a fairly
small group of people. Second, and more
importantly, the licenses it includes expire and
must be decommissioned if you fail to renew
your MAP agreement each year. Every other
example I have here includes Windows licenses
that are good in perpetuity.]
Ready to get started? Pick a category and go.
Page 2: Upgrade offers You can save as much
as 58% off the regular cost of a Windows 7
upgrade if you know how to buy smart. I've
found three options.
Page 3: Special deals for students If you're
enrolled in a college or university, even taking
a single course at your local community
college, you can get Windows 7 Home Premium
or Professional for $30. Students in technical
or design majors can get Windows 7 (and many
other Microsoft programs) for free if their
university or college is signed up for the right
programs.
Page 4: Windows (and much more) by
subscriptions Are you an IT pro, a Windows
enthusiast, or a professional developer? For a
surprisingly low annual fee, you can get access
to a staggering amount of Microsoft software,
including every version of Windows or Office.
There are some restrictions, so be sure to
read the details carefully.
Who's eligible: Anyone running Windows 7
Starter, Home Basic, Home Premium, or
Professional
If you custom-build a new PC, you can choose
the exact Windows 7 edition you want on it.
OEMs get the best pricing, so this is usually
your best option. But if you purchase a
preconfigured PC from an online or local
retailer, you get whatever edition of Windows
they chose to install on it, typically Windows 7
Home Premium for consumer PCs. Outside of
the U.S., Western Europe, and other developed
markets, you might get Home Basic, and on a
netbook you can get the wimpy Starter
edition.
Purchasing a full retail upgrade is one option,
but the Anytime Upgrade option can be much
cheaper. For instance, a retail upgrade of
Windows 7 Professional costs $199.99. If you
have a PC with Windows 7 Home Premium
already installed on it, you can buy the
Anytime Upgrade option for $89.95 direct
from Microsoft. Likewise, you can go from
Windows 7 Home Premium to Ultimate for $
139.95, which is a considerable savings over
the $219.99 retail upgrade price for Ultimate.
(The full price list is here at the Microsoft
Store.) Online retailers like Newegg.com offer
the same deal for a discount of a few bucks,
although you have to wait for a physical box to
be shipped.
Up to 58% Off: Windows 7 Home Premium
Upgrade Family Pack
Expires: "Limited time offer" with no specific
expiration date [Update: as of December 4,
2009, the Family Pack appears to be sold
out in the United States] [Update 2:
Microsoft repeated this "limited time"
offer in Fall 2010; it could expire as soon
as December 31, 2010. See this post for
details.]
Who's eligible: Any multi-PC household
(international)
If you have two or more PCs in your home and
you want to upgrade them to Windows 7, this
deal is for you. This package is only available in
a physical box and (according to Microsoft)
only for a limited time. It includes two DVDs:
one copy each of the 32-bit and 64-bit
Windows 7 Home Premium upgrade installation
media. You get a single product key that can
be activated on up to three different PCs.
In the United States, I found the Family Pack
at the Microsoft Store for $150, but you
should be able to pick it up elsewhere for a
discount of at least $10. Even if you only use
two of the licenses and thus pay an average of
$75 apiece, this is a big savings over two single
upgrade copies at $120 each. If you use all
three upgrades, the cost per machine is $50 or
less.
According to Microsoft, this offer is also
available in Japan, Canada, Germany, the UK,
France, the Netherlands, Switzerland,
Austria, Ireland, Luxembourg, and Sweden.
The license says you can install Family Pack
upgrades on up to three PCs in the same
household, for use by residents of that
household. When I asked Microsoft whether it
was OK to use this license in a home business, I
was told, officially, "There is no restriction
around use of a license for business purposes
conducted within the home," although naturally
they recommended Windows 7 Professional
for those situations.
Nothing in the license prevents you from
mixing and matching the 32-bit and 64-bit
versions on up to three PCs in your household.
But no, you can't share licenses with your
neighbor or your cousin in Peoria.
Up to 50% Off: Buy a new PC, upgrade
your old PC for half off
Expires: [Update: This offer expired on
January 2, 2010]
Who's eligible: Anyone who buys a new PC with
Windows 7 from a participating retailer
Microsoft has publicized this deal on its
website, but retailers seem a little shy about
promoting it. When you buy a new desktop PC
or laptop with Windows 7 included, you can
buy a second upgrade copy of Windows 7 for
use with another PC at a discount. The
estimated price for a copy of Windows 7
Home Premium is $49.99, Windows 7
Professional is $99.99, and Windows 7
Ultimate is $119.99.
According to Microsoft, the following
merchants in the United States are
participating: Fry's, Newegg.com, Staples,
Office Depot, Costco, Best Buy, Radio Shack,
Amazon, Tiger Direct, Walmart, Buy.com, and
The Microsoft Store.
If you go to Newegg, you'll find the offer
available as a Combo Deal with individual PCs.
So, for example, if you buy a Toshiba Qosmio
X505-Q830 you can pick up a second boxed
retail upgrade of Windows 7 for $70-100 off.
I didn't see any mention of the offer in this
week's local ad for Best Buy. Maybe a
salesman would offer me this deal if I shopped
at a local store.
Amazon.com offered the deal on this page, but
I didn't get any clue or pointer to this offer
when I added a new PC to my shopping cart,
and the promotional discount wasn't applied to
my order until I was ready to check out.
If you're planning to buy a new PC anyway, this
deal is worth it, but you might have to be
persistent to get it.
If you are a an eligible university student who
attends an educational institution in the
United States, you can purchase an upgrade
edition of Windows 7 Home Premium or
Windows 7 Professional for $29.99. (That's a
huge savings from the regular price of $119.99
or $199.99, respectively.) You must be
"actively enrolled in at least 0.5 course
credit." Full terms for the U.S. offer are here.
Any college or university that gives you a .edu
address qualifies, as do the eligible
institutions on this list. If you don't have a
qualifying e-mail address, you can still apply
by following these instructions. To apply in the
United States, start here.
According to Microsoft, similar offers are
also available in Japan, Canada, Germany, the
UK, France, the Netherlands, Switzerland,
Austria, Ireland, Luxembourg, and Sweden.
Limitations? The deal is one copy per student.
Digital download is fulfilled through Digital
River, or you can pay $13 extra for a physical
disk. The offer is non-transferable, but the
terms are curiously vague about whether you
can sell or give away the software itself. This
is not an academic or otherwise restricted
license; it is the same upgrade package
available via retail outlets.
Free: MSDN Academic Alliance
Expires: No expiration date
Who's eligible: College/university students in
technical departments (international)
If you are enrolled in a science, technology,
engineering, or math department at an
educational institution that belongs to
the MSDN Academic Alliance, you can get
free software for use in your studies. (There
are also similar offers for students in visual,
illustration, design, and art departments.) The
program also extends to members of IEEE and
ACM. The list of available titles originally
included Windows 7 Professional, but when
word spread of this benefit, both
organizations suddenly had a flood of new
membership requests, virtually all of them
from non-students looking for a freebie.
That inspired this announcement from
Microsoft's Academic Care blog.
The release of Windows 7 through these
subscriptions triggered an unanticipated
situation that put the program at risk: We saw
signs that non-students were joining ACM and
IEEE as student members solely to obtain
Windows 7 through MSDN AA. This infringed
on the intent of the program and the
conditions of the MSDN AA license. As a
result, we decided to remove Windows 7 from
the association MSDN AA memberships while
we evaluate approaches to ensure that the
offering is reaching only the target audience:
students and educators. While we expect to
have a final position on the matter resolved in
the near future, we cannot guarantee that
Windows 7 will be available through this
associations due to the complexity of student
enrollment verification.
So, here's the bottom line: If you want to join
IEEE or ACM, you won't get a free copy of
Windows 7. But if you're a student in a
technical or design course of studies, you
might qualify and you should aggressively
pursue your right to this benefit. You can find
out whether your school is eligible by
searching here. If you're an English or Political
Science major or a non-student, you should
look elsewhere.
If you're an IT pro, technical professional,
journalist, or hobbyist, Microsoft has a
program called TechNet Plus designed to give
you access to a wide range of evaluation
software for a single annual subscription fee.
The price varies by country, and also by
whether you're purchasing as an individual or
on behalf of an organization. In the United
States, the price is $349 for the first year
and $249 annually for renewals. (Both of
those prices are for download-only access; if
you want DVDs shipped to you, you'll need to
pay a higher price.)
What you get for that price is access to a
staggering amount of software, including just
about every version of Windows (desktop and
server) ever made, along with past and current
editions of Microsoft Office, developer tools,
servers, and much more. You get multiple
activations for most products – typically 10
product keys for every Windows and Office
edition. [Update: The number of allowed
activations has been reduced to 2 per
product for the most popular TechNet
subscriptions.] You also get access to premium
Microsoft support: two complimentary
incidents per year.
The software and accompanying product keys
don't expire. So if you decide next year not to
renew your subscription, you can continue to
use the software and keys you downloaded.
So what's the catch? Read the license
agreement carefully! This software is NOT for
use as a replacement for licenses on PCs you
use at home or work. Here's what the FAQ
says:
The license grants installation and use rights
to one user only, for evaluation purposes, on
any of the user’s devices, this may include
devices at home. Keep in mind that you may use
the evaluation software only to evaluate it. You
may not use it in a live operating environment,
a staging environment, or with data that has
not been sufficiently backed up. You may not
use the evaluation software for software
development or in an application development
environment.
For technical professionals who evaluate
hardware and software professionally, or for
hobbyists who want to play around with new
technologies, this is a tremendous deal.
Annual subscription: Microsoft Developer
Network (MSDN)
Expires: No expiration date
Who's eligible: Anyone (international)
The terms and benefits of an MSDN
subscription are generally similar to those
offered to TechNet subscribers, with a few
crucial differences. The biggest difference is
that MSDN is specifically intended for
professional software developers. An annual
subscription gives you access to a wide range
of professional developer tools and pre-
release products.
Every MSDN subscription includes access to
the latest version of Windows with multiple
activations. You can choose from different
levels of MSDN subscriptions. The cheapest is
the MSDN Operating Systems subscription,
which costs $699 for the first year and $499
for renewals. It offers full access to
Windows, toolkits, and SDKs. Prices go up for
other editions: $999 ($649 renewal) for an
Expression Professional subscription, for
example, which is intended for designers and
web developers and includes Windows, Office,
Expression Studio, and Visual Studio
Standard Edition.
Unlike TechNet licenses, which are strictly for
evaluation, an MSDN Premium subscription
specifically permits you to install and use one
copy of the latest edition of Microsoft Office
(currently Office Ultimate 2007), Project,
SharePoint Designer, Visio Professional, and
Office Communicator "for General Business
Use … on one machine for any purpose."
The MSDN license agreement is detailed and
worth reading in full. There's an excellent
summary of your rights as a subscriber here.
This paragraph is especially noteworthy:
Many MSDN subscribers use a computer for
mixed use—both design, development, testing,
and demonstration of your programs (the use
allowed under the MSDN Subscription license)
and some other use. Using the software in any
other way, such as for doing email, playing
games, or editing a document is another use
and is not covered by the MSDN Subscription
license. When this happens, the underlying
operating system must also be licensed
normally by purchasing a regular copy of
Windows such as the one that came with a new
OEM PC.
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