The Virtualization Room

July 2, 2008  12:09 PM

Dissecting bridged-network functionality on Sun xVM VirtualBox for Windows

Rick Vanover Rick Vanover Profile: Rick Vanover

If you have not noticed, I have been on a Sun xVM VirtualBox kick recently. I think it is beneficial to virtualization administrators and managers to be familiar with at least two hypervisors — so why not learn more about xVM?

VirtualBox has a smooth interface for a version 1 release, but the one area that would require the most adjustment is the virtual networking. Let’s take a closer look at network functionality in VirtualBox.

Virtual networking on VirtualBox has a few key differences that VMware users would need to develop an understanding about before fully utilizing the potential of the product. The first difference is the concept of the virtual networking hardware. VirtualBox allows a virtual machine (VM) to have one of four network interface cards virtually assigned. These are the AMD PCNet PCI II, AMD PCNet FAST III, Intel Pro/1000 T and the Intel Pro/1000 MT. This array of virtual adapters allows a VM to have broad support for multiple operating systems, but the corresponding bridging functionality may make network administrators a little uneasy.

Spanning Tree
For Windows systems, VirtualBox uses a spanning tree algorithm from the native operating system bridging that may cause issues on systems with multiple interfaces in managed network environments. The bridged network functionality puts the VMs on the same physical network as the VirtualBox host system. In this fashion, a VM would be able to retrieve a DHCP network from the physical network and interact as if it were placed on the network parallel to the host. Windows XP and Server 2003 products’ bridging functionality is explained on the TechNet website.

Another key difference is that in order for a VM to use the bridged network is the addition of a bridging interface. Adding an interface is fairly straight forward with the use of the VBoxManage command. The following command would add a bridging interface named “VM-Bridge”:

VBoxManage createhostif "VM-Bridge"

Once this command is completed, the VM-Bridge interface is now present in the network connections inventory of the Windows control panel. Then a VM can be configured to use bridged networking with the newly created interface as shown in the figure below:

VirtualBox Bridging

At this point, the VM-Bridge interface can transparently place the VM on the same network as the host when the Windows bridged connections are correctly configured. Note also that in the network configuration you can fully edit the MAC address of the VM. While exceptionally convenient, this can introduce risk for some environments and situations.

Now that we have gone through a quick look at VirtualBox’s implementation of bridging network connections for VMs, I would have to nudge the VMware products to be a little more seamless in the category of bridged networking. By having the VMware bridge protocol binding used instead of a separate series of adapters for the same purpose, VMware’s bridging fits better for most environments.

Make no mistake, the comprehensive VirtualBox networking implementation is fully competitive with VMware. There is much more to the VirtualBox networking implementation available for download in the online user guide in section 6.

July 1, 2008  12:05 PM

Importing VMDK disk files into Sun xVM VirtualBox

Rick Vanover Rick Vanover Profile: Rick Vanover

Sun xVM VirtualBox for Windows offers the capability to import VMware-based VMDK files into a virtual machine (VM), making a migration or cross-platform deployment quite enticing. VirtualBox 1.6.2 does not yet support the Open Virtual Machine Format (OVF) implementation; however, native handling of the VMDK files will suffice for most situations. Let’s go through importing a VMDK file for use in VirtualBox.

The critical tool in VirtualBox is the Virtual Disk Manager (VDM) for disk access. For most of us with a VMware-centric background, this will be a new concept. The VDM is a single tool where all virtual disks are inventoried. This can span multiple locations as well as multiple disk types – such as floppy, CD-ROM, and hard drives. Further, for the hard drive inventory, it is ubiquitous as to whether the disk is a VMware VMDK file or a VirtualBox VDI file. The figure below shows the VDM with an inventory of both VMDK and VDI files:

VDM View

When a VM is created (or when modifying and existing VM), the drive inventory can be specified to create a new virtual disk or use a disk that is listed in the VDM inventory. By managing the virtual disks within the VDM, the VMs can pull directly from this inventory based on your configuration. The VDM can provide disks of all types from remote locations, such as a UNC path or a mapped drive.

There are a few important notes on the use of VMDK files within VirtualBox. First is that the snapshot functionality is not yet supported for VMDK files within VirtualBox. Second, if you intend to boot from the VMDK file, the VM may need boot device modifications. And lastly, the VMDK is modified when used by VirtualBox, so if you go back to using it with a VMware product, depending on what you have done to it – it may not be accessible. For non-boot drives, this should be a transparent exchange.

More information on the use of VMDK files within VirtualBox can be found in the online user guide for VirtualBox in section 5.4.

July 1, 2008  9:01 AM

QLogic and Microsoft taken to task for “benchmarketing” by Chris Wolf

Alex Barrett Alex Barrett Profile: Alex Barrett

Anyone with five minutes of IT experience knows that vendors sometimes publish bogus “benchmarks” that portray their products in the best of all possible lights. Virtualization guru and Burton Group analyst Chris Wolf recently uncovered a particularly spectacular example of this, courtesy of QLogic and Microsoft.

In a release, QLogic Corp., a networking technology provider, said it tested virtual machines running on Windows Server 2008 Hyper-V and attached to a storage area network (SAN) via its 8 Gbps Fibre Channel (FC) host bus adapters, and saw near-native performance of 200,000 I/O operations per second (IOPS).

But, as Wolf discovered, what QLogic failed to mention was that it ran its tests against a very unusual SAN array: the Texas Memory RamSan 325 FC, which uses solid-state storage. Further, the benchmark used block sizes of just 512 bytes, compared with a more real-world block size of 8 K or 16 K.

This left Wolf feeling duped and betrayed:

If I was watching an Olympic event, this would be the moment where after thinking I witnessed an incredible athletic event, I learned that the athlete tested positive for steroids.

Wolf ran this benchmark by a colleague, who calculated that had the same benchmark been performed using “real disks” with latency of 7 milliseconds, it would have limited throughput to a much less impressive 9,142 IOPS. Hardly anything to write home about.

Thanks to Wolf for taking the time to look into this.

June 30, 2008  4:30 PM

Why (or why not) switch from VMware to Hyper-V?

Eric Siebert Eric Siebert Profile: Eric Siebert

Now that Microsoft has finally delivered Hyper-V, everyone is waiting to see how many VMware shops will make the switch. Are there any compelling reasons for a company that already has a large investment in VMware products to switch to another product? Here are some reasons why companies may or may not make the switch from VMware to Hyper-V:

Some reasons why companies may choose Microsoft Hyper-V:

  • It’s Microsoft. Companies that mainly use Microsoft products could switch to get better support for running their products running on virtual hosts and to not have to rely on a separate vendor for virtualization.

  • Cost. It’s definitely cheaper then ESX, but I’m a firm believer that you get what you pay for. Yes, Hyper-V is a lot cheaper then ESX but it lacks the maturity and high-end features that ESX has. It’s probably just a matter of time though before VMware lowers its cost for large enterprises as they have already done with the SMB market with its bundled foundation acceleration kits.

  • Versatility. Hyper-V will pretty much run on any hardware that Windows will run on. ESX only supports a very specific set of hardware. VMware has recently expanded their hardware support and will continue to do so.

Some reasons why companies stick with VMware ESX:

  • Cost (again). Companies with a lot of in-house VMware experience will have to re-train staff to learn Hyper-V and basically start from scratch. There is a large pool of skilled and experienced VMware architects and administrators available today as well as many VMware consulting firms and business partners.
  • Less features. ESX and VirtualCenter have a very rich tool set including vMotion, DRS and HA. Hyper-V lacks the ability to team NICs on vSwitches and their Quick Migration feature requires downtime.
  • Less third-party products. A large number of 3rd party products and add-on’s are available for ESX to enhance it. It will take time for vendors to release products for Hyper-V.
  • It’s VMware. ESX is a mature, stable product that has been around for many years, Hyper-V is a 1.0 product that will take to develop and get all the bugs out of it.

Will I make the switch? Probably not anytime soon. I’ll definitely be looking at Hyper-V and will make my own comparisons, but the lack of certain features is a show stopper for me right now. I’ll keep an eye on Hyper-V to see how it develops, re-evaluating it later as new versions are released.

The competition is going to be great in the virtualization market, as it helps to drive down costs and force vendors to innovate. The race is on between VMware and Microsoft with VMware already miles ahead. Nevertheless, Microsoft has a lot of money and the determination to be on top (take Lotus Domino, Novell Netware and Netscape as examples). Expect Microsoft to slowly whittle away at VMware’s dominance as their product matures and to see VMware to do whatever they can to maintain superiority in the virtualization market.

June 30, 2008  4:04 PM

Protecting virtual disk files from nosy admins

Eric Siebert Eric Siebert Profile: Eric Siebert

I recently came across an article revealing that 1 out of 3 IT administrators have used their elevated privileges to snoop on confidential information. It’s always possible to lock out administrators to sensitive data through operating system access controls, however, a virtual environment opens up other avenues for exposing sensitive data.

With physical servers, the task of imaging a server’s hard drive for offline examination is not always easy. An administrator of a virtual environment can easily and stealthily snapshot a virtual machine to temporarily suspend writes to disk file, make a file system copy of the VM’s disk file from the host server while it is running and then take that copy to a workstation where they can mount it and attempt to gain access to information to which they would normally not have access.

Either by mounting the disk file to an existing VM then adding an additional hard drive to access the information on the drive, or creating a new VM and mounting a live CD to utilize hacking utilities to defeat the operating system security, admins can bypass operating system level controls to gain access to the data simply by making a copy of the disk file and mounting it elsewhere .

Virtual servers open up additional attack vectors over physical servers, illustrating why proper security measures must be utilized to ensure that sensitive data is adequately protected in virtual environments. In addition to properly securing host servers, auditing and logging should also be in place to track all logins and activities on host servers. Administrators typically need access to sensitive data to be able to do there jobs but this access should be limited as much as possible to only what they actually need.

Many administrators snoop because they know they can get away with it. By restricting access and logging events, the 2/3rds of IT administrators who set the better example make snooping more difficult for nosey admins.

June 26, 2008  4:18 PM

Lab management streamlines asset allocation, saves costs

Megan Santosus Profile: Msant

Traditionally, developing and testing applications is a labor-intensive and time-consuming process that requires IT departments to create testing environments that mirror production environments. Once a testing environment is created—with production operating systems, network configurations and the like all painstakingly recreated—the test-and-development crew may need the machines only for a few days before the environment is scrapped. For IT operations, creating and tearing down test environments is just one more activity in already overtaxed schedules.

Virtualization technology – with its inherent ability to quickly create virtual machines – has been widely embraced for test-and-dev applications. Now virtual lab management software further helps IT administrators by automating and consolidating the processes required to establish lab IT infrastructure. Many virtualization proponents view these tools as the perfect antidote to the legwork required to set up and break down lab environments.

Easing IT’s burden
Providers VMlogix, Surgient and, naturally, VMware offer virtual lab management products designed to make the build-and-tear-down process required for test and development faster and easier. (VMware Lab Manager works only with VMware environments.) The software typically enables the configuration of multiple VMs in multiple environments and integrates with third-party quality assurance and testing tools, such as HP Quality Center, Borland SilkTest, IBM Rational Build Forge and IBM Rational ClearQuest, among others. For test-and-dev folks, the payoff of such tools is faster testing and development. For IT operations, the value of such tools has more to do with labor savings and cost overhead.

For about two years, Brian Boresi, manager of client engineering at Sisters of Mercy Health System, has used Surgient’s Virtual QA/Test Lab Management System (QTMS) test applications as part of an enterprise desktop refresh.

Before getting the tool, a subject matter expert would spend more than a week in a central lab testing a new system against core applications. Today, that process has been whittled down to about four hours. “An SME creates testing scripts based on a onetime visit to the lab,” Boresi said. “The virtual test tool automates the scripts which we run in a test environment on a VMware ESX server.”

Theresa Lanowitz, president of voke Inc. , an IT research firm, has studied the benefits of virtual lab management technology and said that such results as Boresi’s are fairly typical. With virtualized lab environments, Lanowitz said, “developers want to test in an environment as close to production as possible, and operations don’t have to set up a lab.”

Self-service provisioning
At Vignette Corp. , a software company, virtual lab technology enables developers and QA testers to provision their own test environments. The company uses LabManager from VMLogix, which includes self-service automation technology, allowing end users to create their own VMs without the intervention of IT operations. “Users now log in and self-service images for themselves,” said Rob O’Neill, Vignette’s senior manager of IT. “With automated workflows, users can check out machines, run them for testing, and then tear them down once they are finished.” The turnaround time for creating test environments ranges from about five minutes to 20 minutes, O’Neill said.

While VM sprawl has become an issue in production environments, it’s also a challenge for test and development. Bart Burkhard, manager of engineering for Overwatch Systems, a provider of software for military command and business information analysis, is currently piloting VMLogix’s LabManager in part to contain VM sprawl. “We have a number of disconnected labs and data centers used by developers and testers,” Burkhard said. “The disconnected labs and parallel projects make physical resource allocation and discovery difficult for us.”

Saving money, improving access to resources
For this reason, Overwatch opted to move test and dev from a physical to a virtual environment, Burkhard said, but the company was wary of the sprawl that could result. With LabManager, Overwatch now maintains a single repository of VMs that track how they are utilized by the company’s test and development staff. “As leases come up for various desktops in the labs, we’ll incrementally replace physical machines with VMs.”

From Burkhard’s perspective, the benefits of using a lab management environment are twofold. From a business perspective, it helps save money on items such as leases, power and cooling because it facilitates the move from physical to virtual environments. For end users, the use of lab management software is getting them access to resources faster. “The time we spent to allocate a machine into a lab with any disk size and memory based on the VMs we have is down from three days to one hour,” Burkhard said.

June 25, 2008  4:19 PM

Microsoft to ship Hyper-V … finally

Alex Barrett Alex Barrett Profile: Alex Barrett

Word has it that Microsoft is finally getting it together and releasing Hyper-V, putting the tech world on notice that it is now safe to exhale.

Phew, we were all about to turn blue.

Has someone ever told you a story about some aging celebrity, and your first thought is, “Wait, you mean they’re not dead yet?’ I probably shouldn’t admit this, but when I read that Hyper-V was coming out, I thought, ‘What do you mean, it’s being released? I thought that already happened!”

My mistake, I had confused the release with another important Microsoft — ahem, milestone — in March: the Hyper-V release candidate (RC).

Excuse me for being flip, but I was bored to tears by this whole Viridian-cum-Hyper-V saga long ago. Two years ago, when I first started covering virtualization, the big news was that Microsoft had made Virtual Server 2005 available for free. Immediately thereafter, VMware returned the volley and made its hosted virtualization platform VMware Server free too, eliminating any real advantage Virtual Server 2005 may have had over the better-established GSX. So much for that story line.

Since then, we’ve lived through name changes, (Viridian to Hyper-V), release candidates, pricing announcements (why $28 dollars, why not $25? $29.99?), delays (will Microsoft meet its 180-days-after-Longhorn deadline? Will it beat it?), feature cuts, feature clarifications (“Quick migration” anyone?), and countless press articles with VMware cast as David to Microsoft’s Goliath — or is it the other way around?

Everything except an actually shipping, nonbeta, nonrelease candidate product.

Until now.

As a journalist, I’m just happy that the wait is over, and we can all stop walking around on tenterhooks, expected to drop everything every time Microsoft comes knocking at our inbox with some virtualization-related announcement that may or may not pertain to the release of Hyper-V.

Now we can all get on with our job of waiting for Microsoft to update us on the status of all the product features that it excised from Hyper-V last year: quick migration, hot add of system resources, increased numbers of CPUs, etc. What a relief!

June 25, 2008  1:48 PM

Overheard on the blogosphere: VMware and Apple can whip Microsoft

Jan Stafford Jan Stafford Profile: Jan Stafford

Chris Wolf  Overheard on the blogosphere:

“Together VMware and Apple could make a run at redefining the desktop (it’s clear that VMware/Microsoft synergy isn’t going to happen). VMware delivers the virtual infrastructure and Apple delivers the OS. Combined, we could have a new generation of desktop delivery that might eventually supplant Microsoft.”

– Chris Wolf  on his blog, Chris

In this post, Wolf — a Burton Group senior analyst and virtualization expert — urges VMware and Apple to get it together and end Microsoft’s desktop dominance. Wolf cogently explains why the operating system-based desktop will fade away as desktop virtualization and new personal desktop models emerge.

What’s your take on where the desktop is going, and which model will dominate in businesses and with consumers? Sound off here, or write to me at

Looking for more info about desktop virtualization? For a complete analysis of current desktop virtualization products and models, check out Andrew Kutz’s article in’s Virtual Data Center ezine.

June 25, 2008  10:24 AM

Getting to know Sun xVM VirtualBox snapshots

Rick Vanover Rick Vanover Profile: Rick Vanover

Desktop virtualization packages rely on snapshots and virtual drive functionality. The de facto functionality standard here is found in VMware Workstation and VMware Server, but the tools in Sun’s VirtualBox may be setting a new standard. Let’s take a quick look at how snapshots and virtual drives work within Sun xVM VirtualBox.

VirtualBox snapshot technology provides the same basic functionality as the VMware products in that they can be taken while the virtual machine (VM) is running or offline.  The snapshots are taken from two different places depending on the state of the VM. For a running VM, the snapshot is taken from the running console as shown in the figure below.


When a VM is powered off, snapshots may be taken in the properties of the VM. This difference is a slight inconvenience, but is an easy learning curve to overcome. Further, if a VM needs to revert to a saved snapshot, this same location is where the VM would be reverted. VirtualBox gives the option to build from the snapshots, so there can be multiple point-in-time restores for a single VM. Snapshots in VirtualBox are kept in the .VirtualBox\Machines\VMName\Snapshots location by default, and are a collection of .VDI and .SAV files. The figure below shows three point-in-time restores for a single VM:


As with all snapshot restores, you should be sure that you want to restore as the reverting process is authoritative to the VM. Reverting to a VirtualBox snapshot taken while the system is running reverts precisely to that point with the VM running, rather than a powered off state. Overall, the functionality inventory of VirtualBox snapshot functions as advertised and brings another positive view to this exciting virtualization platform.

More information on the VirtualBox 1.6.x product can be found in the online user guide.

June 25, 2008  10:11 AM

New virtualization management tools take on VM sprawl

Megan Santosus Profile: Msant

As server virtualization technology makes its way from test environments into production, IT organizations are struggling to keep up with the inherent management challenges involved in dealing with virtual environments.

The ease with which VMs are created makes it that much easier for VMs to be launched and moved willy-nilly regardless of the security and software licensing cost issues, just to name two common problems. Vendors of course have been hip to these challenges. This month, Embotics Corp. released version 2.0 of its V-Commander management software designed to automatically nip virtual sprawl in the bud. One way the software does this is by automatically enforcing policy dictating such things as VM expiration dates and through role-based security access that defines just who can do what in terms of VM creation and migration.

Also this month, Netuitive Inc. revamped its Service Analyzer business service management (BSM) software to include virtualization management capabilities. Nick Sanna, Netuitive’s president and CEO, said the company’s self-learning correlation software can monitor the status of applications across the environment, whether they are physical or virtual. “The idea [behind Service Analyzer],” said Sanna, is to eliminate IT management silos by automating performance management and providing end-to-end visibility into business services.”

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