Virtual Strategy Magazine - 10 Tips For A Successful P2V Migration

10 Tips For A Successful P2V Migration

By George Pradel

published: Wednesday, March 19 2008

When it comes to migrating physical servers to virtual machines, many IT pros have found getting there is not half the fun. Too often, the conversion process is more frustrating, confusing and time-consuming than it needs to be. The time and resources required for conversion are important variables in the overall value and total cost of ownership your virtualized systems will provide. It is crucial to select the right approach for physical-to-virtual (P2V) server migration to minimize risks, keep your project on budget and on track, and your data intact.

There is no single best approach to larger scale P2V conversion initiatives. Solution providers and creative IT pros have found many ways to take physical servers virtual. Each approach can be made to work, but only one is bound to be the most convenient and cost-effective for your project. Successful conversions have just as much to do with the resources an organization makes available - namely implementation time and staff - as the P2V conversion technology or underlying

virtualization platform. To choose the best approach, you need to understand and manage many factors about conversion preparation, execution and post-processing. You also need to know the different types of solutions and their limitations.

Based on Vizioncore's experience from thousands of successful server conversions, we present the following tips for managing the process and selecting the solution that best meets your needs.

1. Assess Immediate & Future Needs

P2V conversion has been done many ways, but only a few approaches have worked well for large-scale migrations. Scalability and speed are two of the biggest differentiators among conversion solutions, so it's important to understand your current and future needs.

Consider not only how many servers need to be converted for the current project, but also if other servers may be converted periodically or in mass (such as taking another department virtual after current projects are completed). It's also important to consider if all physical servers will be converted to the same virtual platform or if multiple virtual environments could be used. Some conversion solutions only support a single virtual environment.

2. Establish Timelines, Deadlines and Budgets

The best approach often depends on the time available to complete the conversion. Most organizations have a deadline for their physical-to-virtual cutover and have limited after-hours time windows to complete it. Therefore the total conversion time and simultaneous conversion capacity of each approach are important considerations. Decide if servers can be taken down for conversion during or after business hours, and determine how much total down time is available before the project deadline. Next, divide the time available by the number of servers being virtualized to determine your requirement for total conversion time allowable per server. Budget is a factor here too -- will overtime or additional personnel be needed to complete the project? Can you afford to extend deadlines if the total required conversion time exceeds the time available?

3. Assess Skills

Personnel and budget questions can't be answered until you determine whether your staff has the skills and time to execute the conversion. Early-generation P2V conversion tools were complex and could only be used by savvy, experienced IT administrators who often had to do their own scripting. Such tools are still offered today, but fortunately, packaged conversion solutions are easier to use, automate many previously manual tasks, and take less time to execute. Assess your internal IT skills and availability to determine which options are available to your organization.

4. Set a Success Rate Goal

P2V server conversion failures are not uncommon. Failures can occur with larger VMs above the 50 gigabyte range, and also when P2V tools do not support certain underlying environments, drivers, or services. Using the time and staff available as guides, determine how many failed conversions you can withstand, set a success rate goal, and use it to help evaluate options. You should be able to find a solution that provides at least a 95 percent success rate.

5. Learn the Options - and Their Limitations

By following the first four tips you'll get a good understanding of your needs. Now it's time to match them to the solutions that are available. There are four basic approaches to P2V conversion. Each is effective in specific use cases and each has some limitations. First, choose the general approach, then begin evaluating specific solution options. Here are capsule summaries of P2V conversion approaches:

Boot CDs plus general cloning and copying utilities. Organizations often use legacy cloning software and supplement it with a virtual machine conversion utility and boot CDs to capture, convert and transfer files. This is the original conversion approach and can be hard to use, especially compared to newer alternatives. It is best for small or one-off conversion projects.
Free conversion tools from virtualization platform providers, such as VMware Converter and Microsoft's Virtual Server Migration Toolkit. For users with a homogenous virtual environment, vendor-supplied free tools are a step up from the copy-and-boot approach. Because free tools are focused on the conversion aspect and do not attempt to automate much of the overall process, the total time required to prep, convert and troubleshoot servers can be lengthy, especially for large servers. Conclusion: good for one-off and occasional conversions.
Packaged conversion tools and solutions such as Vizioncore's vConverter and PowerConvert from PlateSpin. Packaged solutions automate many tasks relating to preparation, conversion and post-processing, and often provide a single user interface for these phases. They provide the shortest total overall migration time, and may include scheduling and advanced simultaneous conversion functions, so they are often most suitable for medium- and large-scale projects. Packaged solutions often support multiple VM formats, but be sure that there is support for your exact virtual platform version. Packaged solution pricing can put them out of reach for some users -- although licensing terms vary greatly by product. It is important to consider total cost of ownership for packaged solutions compared to alternatives, because packaged solutions typically save time by automating multiple tasks, increasing conversion success rates, and saving resources because they can be used by non-specialist and more junior IT staff. Conclusion: understand and manage the economics of your conversion initiative.
Outsourcing to a solutions provider is always an option, and may be the only practical option for organizations with unique needs not supported by packaged conversion applications. Outsourcing is most appropriate for organizations with severe time or personnel constraints. Solution providers often perform conversions using the same set of software and tools available directly to end users, so organizations should evaluate whether the convenience of outsourcing is worth the cost.

6. Estimate the Total Time Each Method Would Take

After initial analysis, one or two conversion approaches might seem appropriate for your project. In reality, there is likely a big difference in how much time and effort each approach would require. One of the most common (and costly) mistakes made in P2V conversion projects is underestimating the total time needed. Be sure to consider physical server preparation, server owner scheduling, the precise steps required to execute the conversion, and post-conversion processing requirements when assessing the total time required.

Remember, many of these tasks can be automated, but there are big disparities in how much automation various solutions provide. These tips should help you identify the approach and solution best suited to your needs. The following tips are for executing the conversion itself.

7. Prep Servers to Streamline the Conversion Process

Conversion times can go down and success rates go up when physical servers are effectively prepared in advance. Steps to perform at this stage include taking inventory of configuration settings, licensing details and IP addresses, installing software patches, defragging drives, cleaning directories, unzipping files and performing other maintenance. You should also verify the network has the bandwidth to transfer the virtualized image, and that the target VM has the memory to accept it. Work with the owner of the server and schedule conversion and subsequent test of the virtualized environment. Finally, set deadlines for change requests and schedule the actual conversion. Some solutions automate these functions, including conversion scheduling and execution.

8. Automate Execution as Much as Possible

Executing the conversion step may take anywhere from about 30 minutes to 20 hours each. The time required has a major bearing on the project cost and the ability to meet deadline. Many processes occur between the time the conversion software is installed and the newly migrated virtual server is booted. Targets and hosts must be selected, configured and named, partitioning may be required, additional configuration is needed for CPU and memory, networks and error conditions must be monitored, the new VM must be named and launched, and the process must be repeated for the next server. The fewer of these tasks the administrator has to perform manually, the faster the conversion will be completed. The actual conversion speeds vary greatly amongst P2V tools and solutions, so be sure to consider speed as you manage all the variables.

9. Verify and Test

The complexity of preparation and conversion itself create opportunities for error, so newly converted VMs must be tested to ensure the conversion was successful. Even when conversion is completely successful there are several post-conversion tasks that must be completed. These include reviewing logs, reactivating services and agents, updating drivers, QC testing, running user-generated scripts, activating and synchronizing the new VM, creating documentation and removing conversion software. These activities must be accounted for when figuring total conversion time requirements, but frequently go overlooked. Once again, the time required to complete them depends on the comprehensiveness of the conversion solution.

10. Repeat as Necessary

For medium- and high-volume conversions, the method must be repeatable to be effective. Solutions developed for these usage scenarios have features to eliminate much of the redundancy for converting dozens or hundreds of physical servers. Scalability is an important consideration. When evaluating options, take into account how much incremental effort is required to convert multiple servers. Keep in mind that many P2V solutions are able to convert multiple physical servers simultaneously. Automated scheduling and execution are also valuable features.

There are many approaches for converting a physical server to a virtual environment, but practical options sharply decline as the size of the project grows. For large-scale server migrations, staff time is often the most expensive element of the virtualization project.

Solutions that save time save money. Expertise and availability are also common constraints. Organizations must consider the end-to-end conversion time when evaluating different approaches, and must determine which tasks they need their conversion solution to handle. By considering and managing these variables, organizations can select the most efficient solution for their needs, and ultimately minimize the risk, time and overall cost of the conversion initiative.

George Pradel, Director, Worldwide Sales Engineering, Vizioncore Inc.: Before coming to Vizioncore, George Pradel was previously a Senior Systems Engineer for VMWare. In 2006, George received the honor of "SE of The Year" and was voted into this award by his manager and his peers. George has more than 20 years of experience in the computer industry, which includes nearly seven years specialization with Citrix technologies. George has presented to thousands at Iforum and VMworld venues, evangelizing the benefits of virtualization. He remains a key member of the lab team at the yearly VMware events. George continues to be heavily involved in the virtualization community and is well known for his use of analogies to transform complex technical concepts into readily understandable and usable knowledge.

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