zPOD makes Windows 7 portable, but not without compromises

The Zinstall zPOD enables portability and speed when backing up a desktop and accompanying applications. However, its usefulness doesn't come without drawbacks.

In August 2010, I blogged about products from an Israeli software company called Zinstall, including Zinstall XP7 and Zinstall zPOD. The engineers at Zinstall have insight into how Windows operating systems are laid out on disk, and they have learned some very interesting ways to turn such disk images into usable and compact virtual machines.

Travelers looking for an alternative to lugging a machine on the road should note that the $89 Zinstall zPOD can enable them to turn a portable USB hard disk -- or better yet, a flash drive, though this comes with some caveats that I'll explore below -- into a ready-to-run version of their usual desktop environments.

Basically, zPOD creates a complete snapshot of a normal desktop environment in the form of a virtual machine (VM), writes that VM to a USB drive, and includes a special runtime module that boots to and runs that VM as the native desktop on any Windows computer that runs it.

The strain of running a large application, however, is probably a low-end analogue of the real heft of a big VM in the Windows environment. You'll want a machine that's at least as fast and with as much RAM installed on it as you had on the PC from which the zPOD snapshot is made. Anything less will quite literally be a real drag.

Zinstall zPOD offers advantages
On the plus side, zPOD is a well-engineered piece of software. The only way to match this program's functionality is to roll up your sleeves and dig deeply into the Windows 7 Preinstallation Environment (a.k.a. Win7 PE). You'd need to customize it to create a compact runtime environment that will let you install and use your favorite applications in addition to the base operating system capabilities.

The best place to learn more about this is in the reboot.pro forums, which include a wealth of topics on specialized boot techniques for Windows 7 -- including several discussions focused on creating bootable USB flash drives for Windows 7 runtime environments. A couple of hours trolling in the forums and playing with related tools (most notably WinBuilder) should convince all but the most fanatical that paying $89 for zPOD is a fabulous bargain in comparison with climbing the necessary learning curve to do it yourself.

The zPOD product can provide an organization the following benefits:

  • It creates a complete copy of whatever Windows 7 runtime environment it's told to transfer to an external hard disk or flash drive -- not only the desktop and applications (at least, those run from C:\Program Files), but also the settings and preferences for Windows and all those applications.
  • The zPOD environment runs in a virtual machine that is separate and distinct from the host operating system, so any changes or additions made inside that environment remain isolated (and protected) from the host environment. All traces of your work stay in the VM.
  • It's easy to turn on 256-bit encryption with password protection for your zPOD environment. Nobody can access its contents without that information.
  • zPOD provides a powerful and instantly functional backup copy for any desktop. Should a primary desktop or PC fail, simply plug in and use the zPOD version to get back to work. Obviously, frequency of snapshots will also dictate how much work or data is lost when switching from a primary to a zPOD-based runtime environment.
  • Zinstall's claims that zPOD is fast are reasonably accurate: I was able to take a snapshot of the 20.9 GB Windows 7 runtime on my 2-GB RAM Asus Eee netbook in less than half an hour. I did the same for the 39.8 GB Windows 7 runtime on my primary production machine, an i7-930-based installation with 12 GB of RAM.

Zinstall zPOD has its downsides, too
With all of its positive attributes, zPOD isn't entirely devoid of downsides. While working with a couple of test installations based on zPOD, I noticed several items worth considering before moving a desktop environment to a portable USB hard disk or USB flash drive (UFD).

  • VMs incur overhead. Cycle for cycle, at least 20% to 25% of normal processing power will be taken up by zPOD and working within a virtual machine environment. An app running inside a VM on the same hardware as the native installation took that much longer to complete normal tasks, and memory consumption increased by about the same margin. VMs also give hard disks and other storage devices a pretty serious workout. Bottom line: Running inside zPOD will never be as fast as native -- unless you're lucky enough to jump from a low-end primary machine to a superfast temporary desktop. (Enjoy it while it lasts!)
  • Overall performance depends on the speed of the external hard disk or UFD. Spending more money on a faster device will show direct productivity gains. Spring for at least a middling capacity solid-state disk (SSD) of 120 GB or larger -- or a big, fast UFD (at least 32 GB, but 64 GB is much better). You'll also want read/write speeds of at least 30/16 Mbps. If you're willing to assume access to an eSATA connection on your host machines, SSDs will outperform UFDs, though some UFD models can plug into eSATA as well as USB ports. Expect to spend around $200 for an 80 GB SSD such as the Intel X25-M models, and about half that amount for a reasonably speedy 64 GB UFD.
  • Don't expect too much from zPOD's compression of desktop contents. My 20.9 GB netbook's desktop still consumed about 18 GB as a zPOD VM, and another 1 GB of code is needed to make the runtime environment work. My 39.8 GB production desktop dropped to 36 GB (and again, it needed 1 GB for software to make it accessible). Even virtual machines need space for temporary files, so save at least 25% more room on the target hard disk, SSD or UFD if taking a desktop on the road in this highly portable format.

Don't get the wrong idea from these negatives: zPOD remains a terrific technology and offers great mobility in a compact form to those who decide to work on other hardware when they go on the road. However, it does put you at the mercy of those who’ll provide you a PC when you're away from your own office, and it will typically reduce performance. Even so, it's a great way to drop the weight of business equipment you must carry.

Ed Tittel is a longtime computer industry writer with over 100 computer books and thousands of articles to his credit. His most recent security book is Computer Forensics JumpStart (Sybex, 2011). Read his IT Career JumpStart and Windows Enterprise Desktop blogs for TechTarget, as well as his posts for PearsonITCertification.com.

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