“Virtualization” is one of those trendy terms these days, much like “green IT” or “cloud computing.” What exactly does it mean, though? To put it simply, virtualization is a description of how a service can be logically separated from the physical hardware that is traditionally used to provide it.
For instance, a local area network (LAN) traditionally was provided by one or more switches. Segmenting the network into multiple networks meant buying separate switches for each subnet. Today, multiple networks can be logically segmented across one or more switches by use of virtual LANs (VLANs).
The logical separation of service from hardware is not limited to networking. Virtualization tends to fall into one of four major categories:
- Virtual LANs (VLANs): As previously discussed, this refers to one or more switches that act as multiple networks.
- Platform virtualization: This uses a hypervisor to abstract operating system(s) from physical hardware, allowing multiple virtual systems to run on a single piece of hardware. Platform virtualization is a major trend in IT that often is discussed in the context of environmental friendliness since it reduces electrical usage and the amount of servers needed. It’s also a major money saver: An average server costs as much as the amount of electricity it uses during a three-year period, and platform virtualization can reduce the number of servers needed by as much as 40-to-1. That is a huge payback.
- Application virtualization: A virtual application is an encapsulated portable application that does not truly get installed.
- Storage virtualization: This provides access to storage while making the location of the physical disk irrelevant. Examples are deduplication, which provides access to more storage than physically exists, and appliances that aggregate multiple storage sources into a single service.
Now let’s delve specifically into the platform virtualization world. There are a healthy number of vendors that provide platform virtualization solutions. The leaders of the pack are Citrix, Microsoft and VMware. Each of these vendors has a certification track, as well.
XenServer is Citrix’s open source virtualization platform. Certification for XenServer is available in each of its four versions: CCA for Citrix XenServer 4 Platinum Edition; CCA for Citrix XenServer 5 Platinum Edition; CCA for Citrix XenServer Enterprise Edition 4; and CCA for Citrix XenServer Enterprise Edition 5.
Although each XenServer certification requires passing only one test, published resources are sparse. Syngress is one of the few publishers that covers it. The Definitive Guide to the Xen Hypervisor is another resource.
Microsoft offers a Microsoft Certified Technology Specialist (MCTS) certification in virtualization “for IT professionals who want to demonstrate their in-depth technical skills in these areas of Microsoft Virtualization.” Microsoft focuses on server virtualization, application virtualization, presentation virtualization and virtualization management.
The certification that aligns most closely with platform virtualization is Exam 70-652, Configuring Windows Server Virtualization.
Microsoft Press doesn’t have any publications that specifically cover Hyper-V. Fortunately, many other publishers have stepped in to fill the void. Two good choices are Windows Server Virtualization Configuration Study Guide and Windows Server 2008 Hyper-V: Insiders Guide to Microsoft's Hypervisor.
VMware is the most mature product in the platform virtualization space, having effectively created the x86 virtualization niche. VMware has two certifications that directly relate to platform virtualization:
- VMware Certified Professional (VCP) on VMware Infrastructure 3: Prerequisites for the VCP certification are attendance at a VMware sanctioned class and subsequently passing the VCP test.
- VMware Certified Design Expert (VCDX) on VMware Infrastructure 3: This is a more advanced certification that requires defense of a design position. It’s a light version of Cisco’s lab-based approach to certifying CCIEs. VCDX candidates must have a VCP certification. They also must submit and successfully defend a design and implementation plan.
Study aides for the VCDX are sorely lacking because the certification is so new. However, there is an abundance of resources to help prepare for a VCP, including a VCP Exam Cram, a VCP test prep book, flash cards and a video.
Shawn Conaway, VCP, MCSE, CCA, is a director of NaSPA and editor of Virtualize! and Tech Toys magazines. He can be reached at editor (at) certmag (dot) com.