6. Applications won’t Migrate to Virtual Machines
If your applications run today on a physical server, they’ll run on a virtual server. Red Hat is one company that guarantees successful physical to virtual migration for applications. Applications rarely connect directly to hardware resources in such a way that would make them unusable on a virtual machine.
7. Virtual Machines Exhibit Lackluster Performance
This entry might not have made the myth list a few years ago, but technology has caught up to virtualization’s hype. High performance disks and controllers, virtualization-enhanced CPUs, gigabit Ethernet and storage-area network devices place this assertion firmly in the myth column. Additionally, virtualization software has improved to the level that virtual machine performance rivals that of physical machines.
8. Lengthy Recovery Times for Virtual Machines
Like any well-executed backup and recovery plan, virtual machine recovery depends on the people who implemented the plan. Virtual machine restore procedures offer quick recovery compared to that of the fastest tape-based system. Often, physical systems require a complete OS reinstall and application restore. This process can take hours. Alternatively, virtual machine recovery requires a simple replacement of the damaged virtual disk files with undamaged ones. Service restoration can take as little as a few minutes. Some administrators choose to use traditional backup technology with virtual machines that may prolong this effort. However, that choice has nothing to do with virtualization itself.
9. Server Virtualization Leads to Server Sprawl
Server sprawl refers to the practice of creating virtual machines that consume virtual host resources with low return for those resources. It is neither a natural progression nor a result of using virtual infrastructure. Server sprawl has more to do with administrative control and policy breakdown than the technology it’s based on, and it happens just as often in physical environments.
10. Server Virtualization Creates Licensing Problems
This myth sprang from the same dungeon as the server sprawl one. It refers to the idea that virtual machines would allow renegade administrators to use too many licenses for a particular product and place their companies at legal risk. Virtual machines are subject to the same constraints as physical machines. For example, Windows systems must perform license activation via the Internet or the system software expires out after a trial period and ceases to operate without proper license activation.
Ken Hess is a freelance writer who writes on a variety of open source topics including Linux, databases, and virtualization. He is also the coauthor of Practical Virtualization Solutions, which is scheduled for publication in October 2009. You may reach him through his web site at http://www.kenhess.com.