Any new technology brings with it changes to the process. Virtualization is no exception. Although there are challenges, they are usually outweighed by the benefits—assuming you understand and address them up front. The following is a list of common issues which must be considered when developing a virtualization strategy.
» License management. It is somewhat easy to track operating system and application licenses in a traditional datacenter or across user desktops. However, licensing in a virtualized world is different and often confusing. Make sure you understand how your vendors license virtual instances of their products and ensure your engineers adhere to licensing policy. It is very easy to bring up VMs without thinking about license availability.
» New skill sets. Configuring, monitoring, and managing virtualized environments require skills not typically found in in-house resources. This is a challenge easily met with training and new hiring requirements.
» Support from application vendors. The big question? Will your application vendor support its software within your selected virtual environment? Does the application even run virtualized? Does the vendor know or care?
» Additional complexity. It should not be a surprise that virtualization adds another layer of complexity to your infrastructure.
» Security. Security on VMs is not very different from standard server security. However, the underlying layers (i.e., the hypervisor and related services) require special consideration, including adjustments to antivirus solutions. Apart from technology differences, the ease with which engineers can build VMs can result in explosive growth of unplanned, unmonitored, and insecure servers. Make sure your change management process is adjusted, policies updated, and staff trained on what is and is not acceptable behavior.
» Image proliferation. This might not be a bad thing unless the images you keep on the virtual shelf are rife with weak configurations or other challenges you might not want spreading like a disease across your datacenter.
» Ineffectiveness of existing management and monitoring tools. As we hinted in the security bullet, your tried and true monitoring and management tools might not include the intricacies of virtualization management.
» Inability of the LAN/WAN infrastructure to support consolidated servers. What happens to your switch when you replace several single traditional servers with one or more beefy hardware platforms running multiple VMs? If you can not answer this or other similar questions, you are not quite ready to make the leap to virtualization.
And these are just the thought-provoking issues we could come with. You may have your own set, which reflect the unique way you do business.
Source of Information : Elsevier-Microsoft Virtualization Master Microsoft Server Desktop Application and Presentation