Creating virtual machines from physical computers is more complicated than just copying memory and disk files to a host. Going virtual can be a complex procedure fraught with challenges and unanticipated roadblocks. If you're getting ready to start P2V conversions, find out what to expect by reading answers to some frequently asked questions.
How should I prepare for P2V conversions?
The first step in any successful physical to virtual (P2V) migration process is determining the physical resources a new virtual machine (VM) will consume. Consolidating several physical machines onto one host without first monitoring actual resource use is a recipe for disaster. Using performance-monitoring tools, such as Windows PerfMon, you can determine how much memory, processing power and hard disk space your current physical computers consume, so that you know whether your hosts have the resources to house those machines as VMs. Monitor resource use through a complete business cycle to identify any potential usage spikes.
Can I virtualize any physical computer?
The simple answer is no. There are several potential roadblocks to P2V conversions that would prevent you from virtualizing some physical computers. Some legacy hardware cannot be virtualized. For example, most major virtualization platforms do not support 16-bit guest operating systems. You can run into similar problems for computers running outdated applications. Applications that use specialized hardware can also sometimes upset a P2V migration. If the physical server uses USB devices or specialized video cards, for example, you may be out of luck.
Do I have to pay for third-party P2V migration tools?
Many virtualization platforms include built-in P2V functionality. The two most popular platforms, VMware's vCenter and Microsoft System Center Virtual Machine Manager, will both work just fine for converting physical machines to virtual machines. Citrix Systems Inc., Quest Software Inc. and Paragon Software Group also offer free P2V tools. There are many other third-party companies that offer their own tools for P2V conversions. Some of these tools perform faster than hypervisor vendors' options and include additional features. If you will be performing many P2V migrations, a faster third-party application could be an attractive option.
What are the differences between P2V migration tools?
In general, the value of a third-party P2V migration product is its improved speed or added features, compared with hypervisor vendors' options. Some products from third-party companies, such as PlateSpin Migrate, can even help you cross platform lines by creating platform independent images -- a useful feature in a multihypervisor environment, or when switching from one vendor to another. Be sure to compare third-party P2V products before selecting one.
When should I bring my new virtual servers online after P2V conversions?
Before bringing new VMs online, be sure your physical server is offline -- and stays off. Most P2V tools automatically power down the physical machine as they bring the VM online, but never manually power on both at the same time. In many cases, you've designed the new VM to run as an exact copy of the physical machine. Imagine having two computers with the exact same domain characteristics communicating on the same network at the same time.