"P2V" is an acronym for "physical to virtual", which is almost exactly what it sounds like: the process of taking
a physical machine and converting it into a virtual one. This is typically done as part of a consolidation effort, where many older servers are "rolled up" into a newer one. But one of the key things about a P2V migration—especially when dealing with Microsoft Virtual Server and Windows installations—is being mindful of the differences between your physical hardware and the virtual machine.
In principle, P2V migration is not all that different from moving a Windows installation from one physical computer to another. It's the same basic process: you make an image of the original system disk and then use that image to build a new system. What's specifically different is a) the endpoint—where you're delivering the image to—and b) how the drivers and hardware settings in the resulting image need to be changed before the image will be bootable in a virtual machine.
These changes often require a bit of work that are not easy to do by hand, and for that reason there are a number of third-party P2V tools to help you make the migration as seamlessly as possible. In this article I'll talk about the most popular and widely-touted tools, describe their functionality, and talk about the advantages and shortcomings of each.
Microsoft Virtual Server Migration Toolkit
Most people start here, if only because Microsoft's own virtual server migration tools are some of the easiest to come by. For one, the tools are free and easily downloaded from the Microsoft Virtual Server site (although you need a Windows Live ID to do so), and are designed to migrate the vast majority of Windows installations that would need to be moved to a virtual machine: Windows NT 4.0 SP6a, Windows 2000 (Server and Advanced Server) SP4, and both the Standard and Enterprise editions of Windows Server 2003.
VSMT uses six steps to migrate a machine (with other guidelines as described by Microsoft):
- Gather system-configuration information from the source computer using a command-line utility.
- Validate the hardware configuration and generate a capture script.
- Run the capture script.
- Generate a new virtual machine on the target Virtual Server 2005 installation.
- Deploy the captured image to the new virtual machine.
- Change any needed hardware settings (networking, storage, etc.) on the new machine.
A number of people have complained about the way VSMT is broken up into so many different stages. It's not like you can do everything from a single console, and many of the commands needed have a fairly arcane (if well-documented) syntax that makes it difficult to get things right the first time. Many who use VSMT report that it's not uncommon to have to run through the whole process several times to get it to work. There are also a few hardware limitations: for one, the primary network adapter in the system you're migrating has to support PXE 0.99c, and the system has to be able to perform a PXE boot. Finally, the system has to be taken offline for at least part of the migration process; it's not possible to migrate while the system is still running.
For those reasons, VSMT is one of the less appealing choices—people use it only if they have no other alternative, no thanks to its fairly unfriendly approach.
LeoStream P>V Direct 3.0
Among the third-party applications that do P2V migration, one of the more widely-touted is LeoStream's P
Another third-party product that is designed to perform seamless migrations is PlateSpin's PowerConvert. It actually encompasses a number of other functions on top of P2V migration—the program's creators tout it as a P2V migration product and a hardware-independent backup-and-restore solution. This actually makes a fair amount of sense, although if you're only looking to purchase a P2V migration system it might seem like overkill. The migration process is also done while the original server is still online, and the source and target machines can be re-synchronized independently later if needed, and no agent is needed on either computer (although restoring to a bare-metal target does require a boot CD). VMWare, XenSource and Virtual Server 2005 are all supported as possible virtual machines, and image file formats from Acronis True Image and Symantec Ghost and LiveState can all be read natively.
The pricing for PowerConvert is also pretty stiff, though, since it's priced by number of conversions: $280 per conversion for up to five conversions, with other pricing plans available.
The BartPE BootCD and the Ultimate-P2V Plugin
Yet another approach, which is much quirkier than the other two described here, involves using the BartPE custom-built boot CD system and a plugin for it which can perform P2V migration. This is probably the most open-ended option, since the BartPE BootCD is heavily customizable, but also the most difficult to implement; setting up the BartPE CD is highly automated, but requires the use of a single Windows XP license to do it legally. This method also requires that the source server be taken offline for the duration of the migration, so if that's not an acceptable option then this solution won't be of much use.
Most of the P2V migration solutions out there right now have a three-way tradeoff. If you want easy, cheap and convenient, then you have to compromise and pick only one or two of those three. LeoStream and PlateSpin's products are easy (wizard-driven) and convenient (migrate without taking systems offline), but it isn't cheap. BartPE and the VSMT are cheap (free), but not convenient (system has to be taken offline) and not all that easy to work with. The bigger and more important the migration job, and the more crucial it is to keep the migrated systems running seamlessly, the more you'll probably want to devote a budget specifically for a migration package that can help you. If you're migrating a less crucial system and want to take things at your own pace and make discoveries, than the noncommercial tools are still handy…just be prepared to spend plenty of time getting to know them.
About the author: Serdar Yegulalp wrote for Windows Magazine from 1994 through 2001, covering a wide range of technology topics. He now plies his expertise in Windows NT, Windows 2000 and Windows XP as publisher of The Windows 2000 Power Users Newsletter and writes technology columns for TechTarget.