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Category Archives: tools

How to manage your Community email notifications

If you are a registered VMTN user, you will have noticed a change in the email notifications you receive since the upgrade to the new platform. They look a little different, and there are new notifications.

For example, there's the "Updates" email that looks somewhat like this:

Screen shot 2011-01-06 at 3.06.46 PM
This email notification contains a summary of updates that could be of interest to you, such as how many replies and views your content has received.

There is also a section listing updates made by the people you are following on VMTN.

You decide how often or if at all you would like to receive this message, as well as any other email notification sent by our community mailer.

Screen shot 2011-01-06 at 3.07.50 PM
At the bottom of the update email, you will find a link to your email preferences page. You will need to log in with your usual community credentials to get there.

This is what my email preferences page looks like:

Screen shot 2011-01-06 at 3.08.45 PM
As you see, I have chosen to auto-subscribe to some of my content, such as documents and discussions, and not others, such as blog posts and bookmarks.

At the very bottom, I have selected the frequency of my community Updates. I like to receive mine twice a week. But you can also opt for daily or weekly delivery, or cancel that email altogether by selecting "never."

Tool: Statelesx | virtualization.info

Stu Radnidge and Shyam Madhavan over at vinternals.com have put together an interesting tool, now at v1.1. Link: Tool: Statelesx | virtualization.info.

This tool allows the VMware administrators to define a configuration
file on a web interface (including details about the virtual
networking, the DRS, the HA, etc.) and associate it to a certain ESX by
the host name. ..

The whole thing, working with VMware
Infrastructure 3.5 only, cuts away the need to configure a new ESX on
deployment and backup its configuration over time. But most of all it
avoids inconsistencies across the virtual infrastructure:



Introducing VAssert

VAssert is a new API, debuting in Workstation 6.5, that uses the Record and Replay functionality that we’ve been talking about for some time now. As you can tell by its name, VAssert is a relative of your standing programming ASSERT debugging tool, but by delaying assert-checking until later when the exact machine instructions are replayed, it can be very fast. That’s some virtualization Deep Magic.

VMware engineers Weiming Zeng and Min Xu give us this guest post on demonstrating VAssert within Apache, and include the Apache patches they used so you can give this a try at home.

A Virtual Buffer-overflow Checker for Apache

by Weiming Zeng & Min Xu

1 Overview

The Record and Replay feature in workstation 6.5 introduces a new guest programming API – VAssert (Virtual Assertions). It is intended that software developers can use it to move expensive program error checking, such as buffer-overflow, to the deterministic replay phase. But does VAssert live up to its promise? As an experiment, we applied VAssert to Apache httpd and wrote a simple buffer-overflow checker by modifying the memory manager in Apache Portable Runtime (APR). Comparing with the same buffer-overflow checker implemented using traditional assertions, the virtual assertions incur 78.77% less runtime overhead.

2 The idea

Our idea to detect buffer-overflow is simple. When allocating memory, append a byte of magic number (the guard) to the end of the memory block; during execution, we frequently check whether the guard is changed. If so, a buffer-overflow is detected.


One of the benefits of this detector is that it is simple to implement. There is no need to intercept all (or most) memory accesses, as other detectors require. But this detector can cause a huge program slowdown if the guard bytes are checked frequently. The slowdown might alter a program’s behavior so that bugs disappear when the detector is activated. With a “virtual” detector, however, the slowdown happens mostly during replay time. Since the replay is deterministic, the detector can find bugs without altering a program’s behavior.

Continue reading

Microsoft’s Virtualization ROI/TCO Calculator gets a failing grade

From our Virtual Reality blog. Link: Microsoft’s Virtualization ROI/TCO Calculator: Our Take | VMware: Virtual Reality.

We Reviewed Microsoft’s ROI/TCO Model

Some of you may have seen Microsoft’s recently released
virtualization ROI/TCO calculator. Briefly, the model purports to offer
an accurate cost/benefit comparison between Microsoft’s Hyper-V
offering and a “Competitive Server Virtualization Solution” – gee I
wonder who the competitive solution is…?  Microsoft is beginning to
advertise the calculator broadly in its partner newsletter and other
email blasts – and we’ve even had customers bring it to our attention.
Mainly, the VMware customers that have alerted us to the Microsoft
ROI/TCO calculator were confused by many of the model’s assumptions and
by the generated results – they wanted our opinion. So, we took a look.

Unfortunately We Had to Give It A Failing Grade

Of course the results were all hypothetical, because Hyper-V is not
yet available, but what we found when running a realistic scenario
through the model and then from reading the report’s fine print, is
that like most Microsoft version 1.0 products, the initial release of
this calculator has numerous errors, contains critical design mistakes,
and completely misses its mark. Any results generated from this model
are so unrealistic as to be completely worthless for accurately
comparing costs and benefits of alternate virtualization solutions.
(Maybe we all need to wait for the SP1?)

In Sum:   ROI/TCO Analysis = Good Idea ; Inaccurate Model = Bad Idea

It goes into deep detail. Aside from the too-high pricing listed for VMware and comparing it to below-list pricing for MSFT, my favorite point:

The Model Incorrectly Calculates Microsoft Licensing Costs
the scenario we ran, Microsoft’s tool assumed 71 Windows Server
Standard Edition licenses for 414 virtual machines running on 71 hosts.
Since each Standard Edition license grants rights to run 1 VM, the
model’s results leave 343 VMs in our hypothetical datacenter running
out of compliance. Microsoft may claim that the TCO/ROI calculator is
not a licensing calculator, but how can it calculate accurate TCO
estimates using inaccurate licensing assumptions?

PowerShell toolkit anticipation builds

Well, once Carter spilled the beans, everybody is now waiting with bated breath for VMware to release the beta of our new curiously-named VI Toolkit (for Windows). The toolkit is powered by Windows PowerShell, a shell/scripting technology that Microsoft appears to have gotten very right indeed. The VI SDK, while extremely powerful, is not for the faint of heart. This toolkit takes that power and wraps it up in a very simple syntax which creates a compelling tool for VI admins.

I’m a Perl guy from way back, and I have to say seeing PowerShell
scripts, er, cmdlets do all sorts of tricks with my VMs without breaking a sweat
makes me grin like a maniac. This is going to be a real boon to VI

Here’s an example from the VMworld hands-on lab manual Automating VMware with PowerShell Lab Manual. How can you not like this? You don’t even need a manual to understand what it does.

get-vm | get-snapshot | where { `
  $_.Created -lt (get-date).addmonths(-1) `

Here’s a round-up of the blog reactions so far.

Dave Marshall played with it at VMworld. Link: VMware administrators find value
in Microsoft PowerShell

I in fact also attended the lab during the show
and found it quite interesting and compelling. For me, this was the
first time I had actually used the PowerShell cmdlets to operate and
manage a VMware environment. I spoke with VMware’s Product Manager of
API & SDK, Carter Shanklin at length. Like the people being exposed
to PowerShell for the first time, Shanklin seemed very energetic about
the possibilities that this scripting feature brings to VMware

Eric Sloof has been working with the toolkit for a while and posting his progress. Link: VMware PowerShell – NTPRO.NL. Here are some of his posts:

Hal is looking for good nuts to crack with our new nutcracker. Link: Call for Script Ideas: VMware PowerShell Toolkit.

Calling all ESX admins!  I am looking for novel ideas for scripts to
write for the upcoming VMware Toolkit for Windows PowerShell.  Yes–I am
offering to do the writing.  I am doing research for a project (details
of which to be announced in the coming weeks), and I could use some
really great ideas of missing functionality or fixes to problems you
have seen while working with VMware Virtual Infrastructure 3.  Pointers
to something cool you have seen done with the VMware Perl Toolkit are
good too.  It’ll be amusing to see how much simpler those will be in PowerShell.  :D

Hal and Andrew Kutz are also having a great discussion about relative complexity and our Perl vs PowerShell toolkits here: TechProsaic
- VMware Perl Toolkit versus PowerShell VI Toolkit
. I don’t think either one really is saying my scripting language is better than yours, but more that the VMware team has done a great job of providing the right level of interface for what admins need to do. Jeffrey Snover actually puts it best on the Windows PowerShell team blog. Link: Windows PowerShell : The Semantic Gap.

Someone could read this blog and walk away thinking, "PowerShell is
great and Perl is crap" – you’d be both right and wrong.  PowerShell is
great but Perl is not crap.  (Hats off to superstar Larry Wall
and Perl, very few people and technologies that have had the level of
(positive :-) ) impact these 2 have had on the industry.  The world is
a better place because that guy was born!)   The difference between the
2 examples is the semantic gap.  The PowerShell example has a very small gap between what you think and what you type. The Perl example has a very large gap.

the end of the day, the semantic gap is "owned" by the people that
provide the instrumentation.   VMWare could have just as easily
provided a PowerShell Script that took just as many lines as the Perl
example or they could have provide a Perl library or script which
provides the semantics of the Get-VM cmdlet.

The good folks at SAPIEN Technologies have a new VI Toolkit (for Windows) book coming out. Link: Coming Soon: Managing VMWare with Windows PowerShell

We’ve a new book in the works: Managing VMWare with Windows PowerShell: TFM. Read about it at http://www.sapienpress.com/vmware.asp,
where you can also read about the author and (once we have them
available) download preview chapters. We’ll be looking for community
reviewers before long, so if you’re an ESX Server user, stay tuned to
this blog for your chance to participate and earn some cash!

Dave Stein wins the award for the best title so far: Oh No They Didn’t!  VMware Getting all Uppity with Mac Daddy PowerShell

I have no doubt you or your RSS reader should stay glued to the VI PowerShell and Developer Center blogs — the VI Toolkit (for Windows) beta is coming your way soon.

SVMotion GUI and VC plug-in from VMware Community

Dave Marshall at the InfoWorld Virtualization Report sums up the last two weeks’ advances in the state of the art of Storage VMotion:

Link: VMware Community Spices Up VMware Storage VMotion

One of the things I like about being in the IT industry is the sense
of community. And as both VMware and virtualization in general continue
to expand in popularity, the virtualization community continues to grow
around it. Case in point, VMware offered a new feature with its VI 3.5
product, Storage VMotion,
and members of the community have already started helping others
through the creation of additional 3rd-party utilities that help expand
the ease of use of this VMware feature.

VMware describes Storage VMotion as a state-of-the-art solution that
enables users to perform live migration of virtual machine disk files
across heterogeneous storage arrays with complete transaction integrity
and no interruption in service for critical applications.

This feature does for virtual machines and storage what VMware
VMotion did for virtual machines and compute capacity. However, members
of the community may not have been overly excited about the way it was

To try and answer that calling, there have already been two
virtualization community members that have taken matters into their own

He has some screen shots of Alexander Giswinkler’s Windows-based GUI and Andrew Kutz’s VC plug-in. As Andrew says at his site Lostcreations. As he says there, this is "the FIRST released, third-party plugin in fact" for VC 2.5. In the thread on the community he  says he’s working on an explanation of how he reverse-engineered the APIs and protocols:

it is the result of a two-week dive into the inner-workings of the VI client
libraries with popular reflection tools (reverse-engineering). l o s t c r e a t
i o n s is working on a white paper that describes how to build VI plugins.

These tools aren’t supported by VMware, so use at your own risk, but kudos to both Alexander and Andrew.


VMjuggler – pong for your virtualization demos

Contrary to what some virtualization vendors have said, zero-downtime migration is a business-critical feature that can completely change your IT processes and enable completely new capabilities — look at DRS and the new Distributed Power Management.

VMware’s VMotion is also rock solid. Richard Garsthagen recently released a little demo app called VMJuggler that demonstrates this nicely for folks that haven’t seen it in action. Richard wrote it for Barcelona TechEd, where he wanted to "show the Microsoft minded crowd that running Microsoft Windows
applications in (VMware) virtual machines works fast, stable and
manageable." Link: VMjuggler: 5 Days of TechED, 10.000 vMotions later….

For the show I created a Windows 2003 64 bit virtual machine and
installed Microsoft SQL 2005 in it. This virtual machine was placed
together with some 100 other virtual machines on our 6 server ESX
environment. I then hit the SQL server with DBhammer to simulate on
average 150 sql clients accessing the database, doing around 1.200
queries a second.

We wanted to show the audience that a
Server like this, can be moved around physical boxes (using VMotion),
without any downtime of the SQL server, so I wrote a small application
called the VMjuggler. This application would initiate a live migration
of my Virtual SQL server every 10 seconds to another physical server.
The VMotion process itself took around 10 seconds, then waited 10
seconds to be moved again. After the 5 days the SQL virtual machine
hopped server more then 10.000 times, with out issues what so ever…

Richard has said he will give a small prize to the first person who wastes enough time generates a million VMotions with VMjuggler. But I actually thought Richard’s comment toward the end was the most interesting.  VMotion has been out since 2003 and old news to anyone already using VMware, but with a virtual machine ping-ponging away in the background at a conference, you quickly get over the ‘gee whiz’ aspect of the technology — yes, it’s cool and it’s real — and can now get to the real question — how is this going to benefit me? Or as Richard says:

Running this demo really allowed us to explain to our visitors that
VMware is more then just a hypervisor company, actually most of the
software we develop is about solving ordinary IT problems like data
protection, resource management, availability, security, provisioning,
etc, we just like to use the virtualized architecture to create these

vm4all.com: The VMware Tools Repository

Great new site from Eric Sloof (soon to be appearing on the right-hand blogroll as soon as I get a moment), vm4all.com. The tagline is "The VMware Tools Repository," and it lists both freeware and commercial utilities you can use with VMware Infrastructure. It has an RSS feed so you can keep up with changes and additions. There are 38 entries so far, with the latest being freeware from Massimiliano Daneri:

  • vdf+ (perl script based on our vdf utility to show mounted VMFS devices)
  • vmSSHjwc (free Java SSH terminal integrated into VI web access)
  • VMCL (free high availability software)
  • VMBK (free hot backup script)
  • VMTSPatchManager (free ESX Server patch manager)

Right now, it looks to be focused on the VMware Infrastructure side — is there a similar tools library for Workstation, Player, Server, and Fusion?

See also: virtualization.info Release search, VMTN User Solutions Forum, and Eric Siebert’s VMware-land.