How Virtualization Improves Software Development

Virtualization technologies aren't just for server consolidation. They've long been valuable tools to anyone writing or testing software. We show how these tools are being used for software development and quality assurance now and identify a few places where developers still want more from virtualization.

The Limits of Virtualization

There are, developers acknowledge, part of the process where virtualization can't help.

"One area where virtualization doesn't help is in stress testing our product, which is a network-based backup appliance," notes 3X's Floehr. "While we could test 10 simultaneous clients virtually, it isn't a true stress test because the 10 clients are only going through, say, four physical CPUs and two NICs, which are constraints that would not exist if they were 10 physical clients in the real world."

"Virtualization does add some complexity," adds MarkMail's Mitchell. "It always adds some latency. But, even worse, you can't rely on VMs to give a clear view of the performance characteristics as you change the underlying execution environment, such as going from development and testing into production."

Finally, Mitchell notes that "The current generation of desktop virtualizers still have too many annoying quirks, bugs and missing features," at least with regard to their use by developers for software development.

"For load testing or scaling, you have to run on the raw hardware, the physical machine," says Microsoft's Mark Friedman. "Performance characteristics, unless you expect to deploy on a VM, are very different. And the same applies to the state of the art for performance measurements; you can't trust the [Physical Machines] you get on a VM currently." Although, Friedman notes, over time he expects this to be fixed.

Also, says Friedman, the para-virtualization approach used by the virtualization industry can change some does change some underlying aspects of the OS, notably the OS drivers. "So if you have a dependency on specific drivers or hardware environment, that will be impacted. For example, there's a virtual NIC, and there's a specific driver. The driver is 'virtualization-aware.' You have to understand that if you need testing against a native set of drivers, you won't see that within a VM. So this impacts people doing driver development, but not web developers, etc."

And, Friedman points out, "if you have a multi-tiered application, which requires several machines, consolidating these to shared hardware means "you get a functional but not a performance test."

Despite those quibbles, virtualization already gives developers real benefits. "Virtualization makes our developers more productive once they learn to work with the technology," says Microsoft's Friedman. "It allows them to spend more of their time in coding, testing and debugging. It eliminates a lot of time and delay spent in set-up and preparation, which isn't where we want them to be spending the bulk of their time."

Daniel P. Dern is a freelance technology writer based in Newton Center, MA. His web site is www.dern.com and his technology blog is TryingTechnology.com.

Join the PC World newsletter!

Error: Please check your email address.

Tags virtualisation

Our Back to Business guide highlights the best products for you to boost your productivity at home, on the road, at the office, or in the classroom.

Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.
Show Comments

Most Popular Reviews

Latest News Articles

Resources

PCW Evaluation Team

Azadeh Williams

HP OfficeJet Pro 8730

A smarter way to print for busy small business owners, combining speedy printing with scanning and copying, making it easier to produce high quality documents and images at a touch of a button.

Andrew Grant

HP OfficeJet Pro 8730

I've had a multifunction printer in the office going on 10 years now. It was a neat bit of kit back in the day -- print, copy, scan, fax -- when printing over WiFi felt a bit like magic. It’s seen better days though and an upgrade’s well overdue. This HP OfficeJet Pro 8730 looks like it ticks all the same boxes: print, copy, scan, and fax. (Really? Does anyone fax anything any more? I guess it's good to know the facility’s there, just in case.) Printing over WiFi is more-or- less standard these days.

Ed Dawson

HP OfficeJet Pro 8730

As a freelance writer who is always on the go, I like my technology to be both efficient and effective so I can do my job well. The HP OfficeJet Pro 8730 Inkjet Printer ticks all the boxes in terms of form factor, performance and user interface.

Michael Hargreaves

Windows 10 for Business / Dell XPS 13

I’d happily recommend this touchscreen laptop and Windows 10 as a great way to get serious work done at a desk or on the road.

Aysha Strobbe

Windows 10 / HP Spectre x360

Ultimately, I think the Windows 10 environment is excellent for me as it caters for so many different uses. The inclusion of the Xbox app is also great for when you need some downtime too!

Mark Escubio

Windows 10 / Lenovo Yoga 910

For me, the Xbox Play Anywhere is a great new feature as it allows you to play your current Xbox games with higher resolutions and better graphics without forking out extra cash for another copy. Although available titles are still scarce, but I’m sure it will grow in time.

Featured Content

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?