It is no secret that I am a huge fan of virtualization. I do not know of any other technology that provides as much agility, flexibility, and cost savings as running many virtual servers on the same hardware. It is very common for me to show clients that they are actually using 10-15% of the resources on their physical servers and how much power and cooling they cans save by virtualizing them.
Many clients are surprised by the different types of virtualization. Everyone has used, seen, or heard of server and desktop virtualization, but not all of them have heard of, nor understand, the benefits and costs of storage, network, and application virtualization.
Server virtualization is the most mature and well understood type of virtualization. This is typically a type 1 (bare metal) hypervisor installed on Intel or AMD hardware. VMware has a huge market share lead and 99% of the fortune 100 companies use their software and for good reason. It has many more features than the other contenders and has a rich 3rd party integration environment. I have been surprised by how little I run into Hyper-V and XenServer in the customers I talk to. I expected Hyper-V to start picking up the small to medium business market with their “It’s free” strategy, but most of the people I talk to understand that there are many costs related to managing and running a Hyper-V infrastructure that need to be taken into account. Red Hat’s KVM is interesting to companies that are already running Red Hat and other Linux OSe’-s, not so much to those running Windows.
Application virtualization is a hot topic for many administrators that I talk to on a daily basis. They are looking for better, faster and easier ways of delivering applications to their end users. Application virtualization is something that we look at in every VDI (Virtual Desktop Infrastructure) project that we work on. The common programs that are used to virtualize applications are VMware’s ThinApp, Citrix’s XenApp and Microsoft’s App-V. These programs help administrators encapsulate programs so that they run in their own private “bubble.” This is very useful when a particular application needs a specific version of Java, .net, or specific dlls, since these can be packages with the application and do not interfere with anything installed on the end users’ system.
Storage virtualization is something that I think we will be hearing more about this year. It is the pooling of physical storage into a single logical storage device. The benefits are that you can use any physical disk storage you have including local disks, and they show up as shared storage and can be used by most hypervisors. Datacore has a very interesting product that does this and provides a good management interface. VMware is coming out with a VSA (Virtual Storage Appliance) in vSphere 5.0 that will take all of the local disks on the ESX or ESXi hosts and present them as LUNs to vCenter, and they can be used the same as any shared storage. This type of virtualization is just getting started and I expect many interesting technologies to come out that will make this a must have for many companies.
Network virtualization is also something that I think we will be seeing more of in the near future. Networking has not changed significantly in the last 20 or so years other than getting faster. Network virtualization will allow you to present your network devices as 1 logical network so that you can take any individual device offline and upgrade it without losing any functionality. Cisco has already started down this path with their Virtual Switching System and I expect HP and the other network providers to develop their own solutions.
Virtualization has changed the way most businesses are running their infrastructure and will continue to do so in many new and interesting ways. Companies that are not leveraging the power of virtualization in all its forms are probably working harder than they have too in delivering their applications to their end users.