IT made simple: virtualization and cloud computing

Virtualization is the technology that splits one physical server into several virtual servers, while cloud computing is a way of using computing resources (servers, storage, applications) on demand, over the internet, paying only for what you use. Virtualization underpins the cloud, but you can also use it without the cloud, on the servers at your office.

As cloud and virtualization technologies have matured, more and more companies, small businesses included, have given up some of the physical servers in their offices: email and documents have moved to Microsoft 365 or Google Workspace, and applications run on virtual servers, on site or in the cloud.

In this article, we talk about cloud technologies and virtualization. We’re not comparing apples and oranges, but rather apples and fruit baskets.

Virtualization = technology

A physical server depends on the hardware configuration it was bought with. Hardware upgrades aren’t easy, because the new components have to be physically installed.

Virtualization solves this problem easily. A virtual server (a virtual machine) runs “on top of” a physical server, without depending on its hardware components. Resources (processor, memory, storage space) are allocated in software, through the virtualization application, called a hypervisor, and can be changed easily. The best-known hypervisors are VMware vSphere (ESXi), Microsoft Hyper-V and Proxmox VE.

For example, to increase the storage space of a physical server, we have to shut the server down, open it up and install new disks. If the server is virtual, the increase is done in software, as a configuration change, without shutting down the physical server.

Typically, a server with high-end hardware specs hosts several virtual servers that run independently of one another, as if they were separate physical servers. What’s more, a virtual server can be moved to another physical server or quickly restored from backup, which greatly reduces downtime.

In short, virtualization is a technology that lets you create several “virtual servers” on a single physical server.

Managed cloud: tell me more →

Cloud = working environment

The cloud is a working environment. It can include virtual servers, containers, standalone applications or even an entire infrastructure.

A cloud environment lets you use computing resources located in different places, pooled and managed centrally. Although the cloud is made up of several data centers, they work as if they were one: a platform with a huge amount of hardware resources.

Cloud computing is a set of principles that makes it easy to use hardware resources according to your company’s needs: you start them when you need them, scale them up or down in a few minutes and pay only for what you use.

To get back to apples and the fruit basket: virtualization lets you “turn” one physical server into several virtual servers, while cloud computing lets you use practically unlimited resources as if they were “a single server.”

What’s the difference between virtualization and the cloud, in short?

• Virtualization is a technology: it splits one physical server into several virtual servers. You can use it on the server in your office.
• The cloud is a way of using resources: you rent them on demand, over the internet, from a provider, without buying hardware.
• The cloud uses virtualization, but adds automation, fast scaling and pay-as-you-go pricing.

What types of cloud are there?

Depending on what you get from the provider, the cloud comes in three main forms:

• IaaS (Infrastructure as a Service): you rent virtual servers, storage and networking, for example in Microsoft Azure or Amazon Web Services, and manage them like your own servers.
• PaaS (Platform as a Service): the provider also manages the operating system, and you only look after the application and the data, for example through a managed database.
• SaaS (Software as a Service): you use the application directly, in the browser or through a program, as with Microsoft 365 or Google Workspace.

Depending on where the resources sit, the cloud can be public (the provider’s resources, shared by many customers), private (resources dedicated to a single company) or hybrid (a combination of on-site servers and the cloud). Many companies use a hybrid model today.

What has changed in virtualization in recent years?

The biggest change came after Broadcom completed its acquisition of VMware on November 22, 2023. In December 2023, VMware announced it was dropping perpetual licenses and moving to subscriptions, which raised costs for many companies. Since then, some companies have switched to other platforms, such as Microsoft Hyper-V or Proxmox VE, or moved some of their servers to the cloud.

The operating system version on your servers matters too: Windows Server 2012 and 2012 R2 reached end of support on October 10, 2023, and Windows Server 2016 reaches end of support on January 12, 2027. A virtual server is easier to migrate than a physical one, but the migration has to be planned ahead. See also the article on the problem with end-of-life (EOL) technology.

What should you choose for your company?

There’s no single right option for every company, but the rules below fit most cases:

1. Email and documents usually move to the cloud, to Microsoft 365 or Google Workspace. See also how to work from home with Microsoft 365.
2. Applications that need fast access from the office (for example, some accounting or production software) can stay on a virtualized server on site.
3. Servers that need to be accessible from anywhere can run in the cloud or in a data center.
4. Wherever your data lives, you need backup, with a copy kept separate from the main system, for example through Backup as a Service. The cloud provider keeps the service running, but backing up the data usually remains the company’s responsibility.
5. Compare costs over several years: the cloud requires no hardware investment, but monthly subscriptions add up.

RezolvIT is an IT outsourcing company experienced in implementing cloud technologies and helping companies let their employees work from home. If you’d like to find out which option suits your company, see our IT infrastructure services or ask for a free IT audit.