Many people believe that cloud computing requires server (or desktop) virtualization. But does it? We will look at using virtualization without cloud computing, cloud computing without virtualization, and then look at using both together. In each case, we'll look at where each deployment might be most useful, some use cases for it, and some limitations.
This white paper examines the relationship between cloud computing and virtualization. Many people believe that cloud computing requires server (or desktop) virtualization. But does it? We will look at using virtualization without cloud computing, cloud computing without virtualization, and then look at using both together. In each case, we'll look at where each deployment might be most useful, some use cases for it and some limitations.
Virtualization without Cloud Computing
Most organizations are virtualized without cloud computing. According to recent surveys, approximately 60 percent of all servers today are virtualized. Virtualization is deployed in businesses of all sizes and affects all industries, organizations, governments, and so forth. Virtualization projects typically start with compute (i.e., server) virtualization, as it is usually the easiest to virtualize and provides the greatest return on investment. This is what is most commonly thought of as "virtualization."
However, more can be virtualized. Both networking and storage can be virtualized. Network Functions Virtualization (NFV) refers to the virtualization of traditional networking functions such as switching, routing, and load balancing. It can include firewalls, Intrusion Detection or Prevention Systems (IDS/IPS), antivirus management and more. Often, NFV is combined with Software Defined Networking (SDN) to automate management of the various physical and virtual network components.
Many vendors also offer Software-Defined Storage (SDS), including traditional vendors, such as EMC, as well as companies that have specialized in SDS for years, such as Data Core. The idea is to use commodity storage devices, often installed in servers, and virtualize access to them so the local storage inside each server gets pooled together and becomes visible as shared network storage.
When virtualized compute, networking, and storage are combined, the result is the Software Defined Data Center (SDDC), which promises a great deal of automation and scalability. Many companies will go to this point and stop.
What is left undone if cloud computing is not also introduced? The self-service provisioning of the VMs necessary for the business workloads to run. It often takes days or even weeks for a VM to go through the approval processes at an organization and for a virtualization administrator to get the necessary VMs created and made available to the users. This decreases a company's agility and often leads users to find a cloud platform on their own, outside the control of IT. This can lead to security issues for the organization, as well as less demand for IT resources, which if taken to the extreme, would drastically reduce or eliminate the need for IT at the company.
So what are some good use cases for using virtualization without cloud computing? Small businesses that don't have an extended VM provisioning process. Medium-sized businesses may also be OK with virtualization only, especially if they don't have developers or others that need VMs provisioned quickly.