What is virtualization?

Server virtualization

Server virtualization technology enables the creation of multiple virtual servers from a single physical server. It helps organizations to cut costs, drive efficiency, and scale easily.

What is server virtualization?

Server virtualization uses the resources of a single physical server to create multiple virtual servers - also known as virtual machines or VMs. Each virtual server is isolated from the others and is allocated its own operating system, applications, storage, CPU and other resources. To create, run and manage the virtual machines, a software layer called a hypervisor sits between the virtual and physical servers. This enables communication between the virtual and physical machines.

What are the three types of server virtualization?

Full virtualization	Para-virtualization	Container-based virtualization
Full virtualization uses a hypervisor to create and manage virtual machines (VMs) on a physical server. Each VM is totally independent and runs its own operating system. As each VM is isolated, this ensures that issues on one VM won’t affect the others on the network, making it a reliable and secure solution.	With para-virtualization, the whole network works together as one, with the virtual machines all being aware of each other. As each VM isn’t fully isolated, the hypervisor uses less processing power to run them, which can result in increased performance and more optimised resource allocation.	Instead of using VMs and a hypervisor, container-based virtualization uses containers to virtualize applications and their dependencies. Each container is isolated from the others and virtualizes the host operating system. It is lightweight, resource-efficient and makes deployment faster.

Virtualization solutions to support your enterprise

At OVHcloud, we offer several server virtualization solutions. Our Advance dedicated servers are ideal for hosting virtual machines and containers, with AMD Secure Encrypted Virtualization (SEV) technology built in to protect your data. We also offer virtual private server (VPS) solutions, plus a wide portfolio of Hosted Private Cloud solutions in partnership with VMware and Nutanix.

Key benefits of server virtualization

Server virtualization offers multiple benefits for modern organizations, including:

Cost savings

Server virtualization consolidates multiple virtual servers onto one physical machine. This reduces the need to purchase physical hardware, which is usually a significant CapEx investment that also requires maintenance, power consumption, and datacentre space.

Scalability

With server virtualization, virtual machines can be scaled up or down rapidly on demand, without the need to deploy additional physical servers. This makes server virtualization a flexible, agile and scalable solution, enabling businesses to adapt to change more easily.

Resource allocation

Using server virtualization, IT teams can allocate resources dynamically depending on the demands of each VM, which helps avoid over-provisioning. Running multiple virtual machines on a single physical server also maximises the server’s capacity.

Security

Server virtualization isolates virtual machines, enabling different workloads and applications to be kept separate from each other. This reduces the risk of security breaches affecting the entire network. Traditional security hardware, such as firewalls, can also be replaced with virtualized versions, which are much more cost-effective.

Simple management

Virtualization solutions can be managed using a single centralized console. This gives IT teams visibility of the entire virtualized infrastructure, leading to easier monitoring and control. Tasks such as maintenance can also be automated, helping teams to save time.

Sustainability

Server virtualization reduces the need to run physical machines, leading to lower energy consumption and a smaller carbon footprint. This helps organizations to align with corporate social responsibility and green initiatives.

Support for legacy systems

Legacy applications and operating systems can still run on virtualized networks, even if your physical servers are new, modern machines. This makes migration of legacy systems easier and supports a faster digital transformation for your business.

Disaster recovery

Virtualization solutions normally have backup and disaster recovery features, such as cloning and snapshots. Also, if you need to migrate virtual machines between physical servers, you can migrate them easily with minimal downtime for your business.

How do I choose a server virtualization solution?

When exploring virtualization solutions for your organization, you’ll first need to define your specific needs around scalability, performance, number of virtual machines required, and resource requirements. Then, we recommend considering the following:

Tip 1: Select the right hypervisor

There are two types of hypervisor: Type 1 (bare metal) and Type 2 (hosted). Because Type 1 hypervisors run on the hardware, they have direct access to server resources. This makes them better in terms of performance, and for this reason, Type 1 hypervisors are recommended for enterprise cloud computing environments. However, if you plan to use virtualization for testing and development, a Type 2 hypervisor would suit your needs better. These hypervisors run on top of the host operating system, offering ease of installation and flexibility. In either case, ensure that you also compare the features offered by different hypervisors, such as snapshots, live migration, and simple resource management. Make sure it suits your specific business requirements.

Tip 2: Evaluate features and tools

Server virtualization solutions come with a range of features and tools. To make things easy for your IT team, look for platforms with a user-friendly interface, automation capabilities, security features, and a simple centralized management hub. You should also assess how compatible the solution is with your existing infrastructure i.e. hardware, networking, backup, storage, security, applications and operating systems. This will make adoption and maintenance much easier, as well as ensuring you don’t have to purchase additional infrastructure purely to fit the virtualization solution.

Tip 3: Consider costs and vendor reputation

Cost is one of the main reasons to adopt server virtualization. It enables organizations to drive down their IT expenditure by reducing the amount spent on hardware, energy and maintenance. To ensure you’re getting the best value, compare different virtualization solutions based on their total cost of ownership i.e. the cost of everything from licensing fees and support to maintenance and additional hardware requirements. At the same time, consider the reputation of the vendor – how long have they been in business? Do they have good customer feedback? Is their support adequate, and do they provide regular technical updates and patching?

Which type of server virtualization is right for me?

The answer to this question depends on your specific business requirements.

Full virtualization with a Type 1 hypervisor is the most common virtualization approach for enterprise cloud environments. This combination delivers the security needed by large organizations and it can accommodate a diverse range of applications and workloads. Using a Type 1 hypervisor offers direct access to resources, making it more efficient than a Type 2 hypervisor, which is better for spinning up testing environments. Full virtualization is compatible with many different operating systems; however, it can be expensive and resource intensive.

Para-virtualization delivers higher performance and efficiency than full server virtualization, as it has better communication with the hypervisor layer. You can choose a Type 1 or Type 2 hypervisor, depending on your specific needs, but in both cases, para-virtualization requires modifications to the guest operating system. Also, as the virtual machines are not fully isolated on a para-virtualized network, issues that occur in one VM are likely to spread. It also has limited compatibility with some operating systems.

Container-based virtualization is the most lightweight method of virtualization, being ideal for hosting microservices and highly scalable applications. As it doesn’t use a traditional hypervisor, you also won’t need to consider whether to use a Type 1 or Type 2 hypervisor. However, it has some of the same disadvantages as para-virtualization, with VMs not being fully isolated, and limited operating system compatibility.

What is server virtualization in green computing?

Server virtualization offers an effective solution for organizations looking to adopt greener technology or meet their overall sustainability goals. Here’s how:

Reduced energy consumption
In server virtualization, multiple virtual machines are created on one physical machine. This eliminates the need to power lots of physical servers in a datacentre, leading to reduced energy consumption and a smaller carbon footprint.
Reduced waste
As server virtualization enables more efficient resource allocation, this can reduce the need for hardware upgrades and replacements, thus extending the lifespan of physical servers and other hardware. This reduces the environmental impact associated with hardware manufacture and disposal.

How is server virtualization different from network virtualization?

Both server virtualization and network virtualization work by virtualizing the resources of physical server hardware. However, whilst server virtualization uses this abstraction layer to create and run multiple virtual servers, network virtualization uses it to virtualize network components. It creates an isolated virtual network, as opposed to virtual servers. The primary goal of network virtualization is to improve resource efficiency and segmentation, whilst increasing agility and flexibility. It enables IT teams to isolate networks and manage and scale them easily.