Server Virtualization

What is Server Virtualization?

Server virtualization abstracts server software from hardware on a guest/host basis, enabling multiple virtual servers to run on a physical device. It is the basis for cloud computing and hybrid cloud.

  • How does server virtualization work?
  • Server virtualization benefits
  • Server virtualization disadvantages
  • What are the types of server virtualization?
  • HPE and server virtualization
How does server virtualization work?

How does server virtualization work?

Server virtualization lets different operating systems and applications operate on one physical server. Here's a simplified explanation of how it works:

  • Hypervisor: The hypervisor is the software layer that powers server virtualization. It separates the server's hardware from its virtual computers and assigns server cores, memory, storage, and networking to virtual machines.
  • Virtual Machines (VMs): Virtual machines are software simulations of actual computers. The operating system and applications operate separately on the same physical server as the other VMs. Each VM uses the hypervisor's virtualized hardware resources like a physical server.
  • Resource allocation: The hypervisor dynamically distributes physical resources to each VM. In case one VM needs more CPU and another needs more RAM, the hypervisor can adjust the resource allocation.
  • Isolation: The virtual machines are segregated, so if one crashes or faces troubles, it doesn't impact the others. The hypervisor maintains VM connectivity and secures their independence.
  • Hardware utilization: Server virtualization optimizes server hardware. Virtual machines can run several operating systems and applications on the same hardware, optimizing resource usage and decreasing the need for actual servers.

Server virtualization abstracts actual hardware and allows numerous virtual environments on a single server, improving IT infrastructure flexibility, scalability, and efficiency.

Server virtualization benefits

What are the benefits of server virtualization?

Benefits of server virtualization for businesses include:

  • Cost savings: Consolidating several virtual servers onto fewer physical servers reduces the costs of hardware, power, cooling, and data center space. Virtualization optimizes hardware use, decreasing the requirement for physical servers.
  • Improved efficiency: Virtualization allocates CPU, memory, storage, and network bandwidth to virtual machines as needed, improving resource usage. This flexibility prevents resource waste and allows demand-based scaling.
  • High flexibility and scalability: Virtualized environments are flexible and scalable. Add or delete virtual machines, tweak resource allocation, and swiftly deploy additional servers as workload demands change. This adaptability lets companies adapt quickly to business demands.
  • Enhanced disaster recovery and business continuity: Virtualization encapsulates virtual computers into files that can be backed up, replicated, and restored to substitute hardware. Virtualization also permits the live movement of virtual computers across real servers with minimum downtime.
  • IT Management: Virtualized environments are more accessible and centralized than physical servers. Virtualization management solutions let administrators monitor performance, automate processes, and deploy new virtual machines quickly. Centralized management cuts administrative costs and boosts efficiency.
  • Isolation and Security: Virtualization isolates virtual machines, preventing applications and workloads from affecting others. Virtualized environments can be protected by hypervisor-level firewalls, intrusion detection systems, and encryption.
  • Testing and development: Virtualization lets developers easily create isolated test environments that resemble production systems, speeding up the time to market for new apps and services.
  • Legacy application support: Virtual machines let businesses run legacy apps on contemporary technology. Businesses can prolong the legacy application lifecycle without maintaining outdated hardware.

Server virtualization is essential for current IT infrastructures due to cost savings, efficiency, flexibility, resilience, and simpler management.

Server virtualization disadvantages

What are the disadvantages of server virtualization?

Server virtualization has several advantages, however it also has disadvantages:

  • Overheads: Due to the hypervisor layer, virtualized workloads can perform worse than on actual hardware. Modern hypervisors are efficient, but applications with high CPU or I/O requirements can be impacted.
  • Resource contention: Virtual machines share CPU, memory, storage, and network bandwidth. Unmanaged resource contention across VMs might degrade performance or cause unexpected behavior. To prevent conflict, administrators should divide and manage resources carefully.
  • Single point of failure: Despite its resilience and disaster recovery benefits, virtualization creates a single point of failure—the hypervisor. Hypervisor failure can impact all virtual machines on that host. High availability and redundancy can reduce this risk, but critical workloads should be considered.
  • Complexity: Managing virtualized systems becomes difficult as the number of virtual machines and hosts increases. Administrators should understand virtualization technologies and how to monitor, deploy, and troubleshoot virtualized infrastructure. Interdependencies between virtual machines and compatibility concerns might add complexity.
  • Licenses: Virtualization software and management tools can cost more to license, but they can save hardware and operating costs. Software licensing fees can grow in virtualized settings depending on the number of virtual CPUs or virtual machines.
  • Security risks: Hypervisor layer vulnerabilities and virtual machine isolation threats are new security concerns with virtualization. A hacked hypervisor can provide unwanted access to many virtual machines. Administrators should use network segmentation, encryption, and patching to reduce these risks.
  • Performance tuning challenges: Latency-sensitive applications and workloads with specialized needs might make virtualized performance tuning difficult. To optimize performance, administrators should alter virtual machine settings, resource allocations, or sophisticated capabilities like CPU pinning and storage tiering.
  • Vendor lock-in: Adopting a single virtualization platform can make migration to other alternatives difficult. Companies should assess the long-term effects of their virtualization strategy and consider interoperability and portability.

Despite these shortcomings, server virtualization is a strong and extensively used technology for boosting resource efficiency, flexibility, and IT operations. Planning, implementation, and administration can solve many of these issues to maximize virtualization's benefits.

What are the types of server virtualization?

Types of server virtualization

Full virtualization

By far the most popular form of server virtualization, full virtualization means that a designated hypervisor works directly with a physical server to monitor and abstract its resources and then distribute those resources to its associated virtual machines as necessary. Full virtualization keeps each of these VMs separate from the others, with each VM running its own operating system (OS).


Para-virtualization is another form of server virtualization and is like full virtualization in its component pieces. The main difference between the two is that each VM is aware of the others and the number of resources their OSes are using, meaning they can then work together more efficiently.

OS-level virtualization

In OS-level virtualization, virtualization occurs within the physical server’s OS rather than being accomplished via a hypervisor. Because of this, the VMs must run the same OS as the physical server, although they still function separately from one another.

HPE and server virtualization

HPE and server virtualization

HPE offers you an extensive, adaptable portfolio of server virtualization and storage virtualization solutions. Partnering with HPE for server virtualization means you get fast deployment, performance at scale, efficient use of server and storage resources, as well as the ability to deliver high availability. When you combine HPE server virtualization with an HPE storage platform, you can increase the agility, reliability, and scalability of your mission critical applications.

HPE GreenLake for Private Cloud Enterprise

Related topics

Cloud Computing

Hybrid Cloud