What is virtualization? If you are here it’s because you are interested in learning and understanding more about virtualization. During this post, I will explain the concept and technology behind virtualization from a high level, and I hope you can provide me with your feedback or questions in the comment section below.
Before getting into the main topic of this post, let’s go back a few years back. This will help us understand the importance of this technology and will also help in understanding why it revolutionized the way data centers are managed and designed today. A few years ago, IT organizations will purchase physical servers that will run specific roles. An example of this was the need for a physical server dedicated to run the backups for the environment, another physical server dedicated as a domain controller and a third one needed to run as an exchange server. Depending on the application or purpose these servers provided, they needed a specific amount of RAM, CPU, and Storage. There was also other hardware needed such as external storage, network switches, etc. As organizations needed more applications to run their business, servers were added to the datacenter. The addition of servers into the racks also called for additional storage and networking. All these changes added costs, management complications, and introduced complexities into the environment, etc.
Administrators needed a better way to manage an always growing environment and doing so in a way were costs were also improved. Virtualization started as a concept many years ago, but it was until the late 90s early 2000s when data center administrators started using this technology for server virtualization. There were and still are, many options available for virtualization, some of this are open sourced and some are provided as paid options. The most commonly used today for its maturity and ability to execute its the hypervisor created by VMware called ESXi vSphere.
At a high-level virtualization converts or virtualizes the physical required hardware needed to run a server such as memory RAM, CPU, storage, networking, etc. into virtual components. This is accomplished by a hypervisor which is installed on top of the hardware, similar to how an operating system was installed on a physical server. By doing this the administrator is able to run multiple virtual servers, which in turn can provide different roles just like before, but instead of having dedicated physical servers for each of these roles, they will run as virtual machines or VMs on one physical server. Each of this VMs will get whatever RAM, CPU, and storage it’s assigned by the administrators. As the environment grows and to be able to add redundancy and high availability (HA), more physical servers are needed. You can add multiple physical servers into one cluster which provides ease of management. The cluster will need external storage, and this storage will need to be shared among the physical servers running the virtualization software or hypervisor. By doing this, the administrator is able to move VMs from psychical to physical server, and automatic HA can also be implemented. Within VMware the ability to move a VM from one physical server to another it’s called vMotion. Virtualization reduced costs, improved the way servers are managed, backed up, and restored. It also improved the way datacenters are designed for disaster recovery scenarios.
There are many other benefits and details that make this magic happens but, for the purpose of this post we have only discussed the virtualization technology form a high-level perspective. Virtualization opened the door to many other technologies being introduced today such as the cloud, containers, automation, orchestration etc. We will be discussing these topics in other post throughout this series of What Is but for now, thank you so much for stopping by and I look forward to hearing from you.