VMTN Blog

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:

 

 

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.

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
In 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?

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 admins.

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 environments.

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:

• The VI3 Windows Toolkit and .net integration
• Create multiple VM’s using PowerShell
• PowerShell Snapshot Remover
• Pipe VMware PowerShell into PowerGadgets

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. 

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.

At 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.

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 implemented.

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

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.

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 solutions.

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.