What is virtual machine server?

A virtual machine (VM) server refers to a physical server that uses virtualization software to enable multiple virtual machine instances to run on a single physical server. Virtualization software, such as VMware, Hyper-V or VirtualBox, allows one physical server to function as multiple isolated virtual servers.

What is virtual machine server?

Benefits of virtual machine servers

Virtual machine servers provide several key benefits:

  • Resource optimization – Enables multiple virtual servers to share the CPU, memory and storage resources of a single physical server. This improves server hardware utilization and efficiency.
  • Isolation and security – Virtual machines are isolated and separate from each other even when running on the same physical server. This improves security and prevents issues affecting one virtual server from impacting others.
  • Flexibility and scalability – It is easy to provision new virtual servers on demand to meet changing workload needs without buying new hardware. This makes scaling infrastructure up or down faster and more cost-effective.
  • Portability and encapsulation – Virtual servers can be easily migrated across different physical servers with no changes. Encapsulating the full server environment into a set of files improves portability.
  • Disaster recovery – Maintaining replicated copies of virtual servers on remote physical servers facilitates faster and easier disaster recovery. Virtual servers can be quickly brought online in case of failure of the primary physical server.

Types of virtual machine servers

There are two main types of virtual machine servers:

Hosted VM servers

These are virtual private servers rented from a cloud or web hosting provider. The hardware infrastructure is owned by the provider while customers rent virtual slices.

Key features:

  • Shared resources – vCPU, memory and storage are shared across customers
  • Self-service provisioning of additional resources
  • Provider manages the physical servers
  • Cost-effective and flexible capacity

On-premise VM servers

Refers to virtualized servers hosted on a company’s own data center infrastructure and hardware. Provides greater control and customization.

Key features:

  • Dedicated vCPU, memory and storage resources
  • Tailored to specific application needs
  • Company manages the physical hardware
  • Hypervisor provides virtualization capabilities
  • Requires upfront infrastructure investment

Main components of a VM server

A virtual machine server environment consists of the following key components:


Virtualization management software that enables multiple VMs to run on a single host. Examples include VMware vSphere, Microsoft Hyper-V, and Citrix XenServer. Responsible for resource allocation and isolation between VMs.

Virtual machines

These are the guest virtual servers or virtual clients created and running as independent entities with their own set of virtualized hardware resources on top of the physical server hardware. Different OS environments can run within each VM.

Management software

Software tools to manage, monitor, backup, migrate and automate various processes across VMs and physical hardware resources. Helps administer the virtual infrastructure efficiently.

Physical hardware resources

The underlying CPU, memory, storage and network hardware that provides the resource foundation for building the virtualized environment. Now supports advanced functionality like nested virtualization.

Additional virtual components

Virtual switches manage communication between VMs and physical network interface cards (NICs). Storage spaces like virtual disks partition and allocate storage capacity to VMs.

Virtual machine server performance factors

Several key factors impact the performance of virtual infrastructure:

Resource allocation

Ensuring appropriate vCPU, memory, storage and network bandwidth allocation for VMs based on actual utilization and workload demands. Under or over allocation can degrade performance.

Hypervisor overhead

Optimized and less resource-intensive hypervisors translate to lower virtualization overhead and better VM performance. Hypervisor has to coordinate across physical and virtual layers.

Storage performance

Fast storage connectivity technologies like SSDs and Fibre Channel enhance VM storage IOPS and access times significantly. Network-based solutions can also work.

Physical hardware advances

Latest multicore processors, nested virtualization support, PCI pass-through, NVMe storage connectivity and speed increases for memory and interconnects boost hardware performance for virtual workloads.

Setting up and configuring virtual machine servers

Following are the key steps to set up and configure a virtual machine server environment:

  1. Choose server grade hardware systems with robust specifications – multicore CPUs, adequate RAM, redundant storage, backup power supplies and fast network connectivity.
  2. Install a Type-1 enterprise-class hypervisor like VMware ESXi bare metal directly on the physical server hardware.
  3. Set up hypervisor management networking and storage disks – create or connect to shared networked storage spaces for hosting VM files.
  4. Use the hypervisor management interface to start creating VMs specifying compute, memory, storage and networking resources per VM according to workload need.
  5. Select VM hardware characteristics like vCPU cores, number of vNICs, virtual storage disks. Install guest OS and applications per VM.
  6. Implement high availability capabilities like live VM migration, fault tolerance, distributed resource scheduling for load balancing across infrastructure.
  7. Monitor resource utilization across physical and virtual infrastructure and optimize allocation between VMs.
  8. Scale up single VM resources or clone more VMs to address growth and maintain performance standards.

Key takeaways

  • Virtual machine servers allow a single physical server to function as multiple isolated virtual servers leading to better resource utilization.
  • Two main virtual server types – hosted VMs through cloud/web hosting providers and on-premise servers managed internally.
  • Hypervisors like vSphere along with VMs, management software and hardware resources form the main components.
  • Allocating resources smartly, reducing hypervisor overhead, improving storage performance and using latest hardware boosts efficiency.
  • Carefully specifying VM vCPU, memory, networking and storage during provisioning, monitoring utilization and scaling up accordingly helps manage capacity and maintain performance.


Virtual machine servers revolutionized computing infrastructure by introducing a virtualization layer that enables running multiple VMs isolated from each other on top of shared physical hardware. This provides tremendous flexibility to provision compute and storage capacity on demand while optimizing resource usage. Hypervisors make the virtualization possible by virtualizing the hardware environment for individual VMs. While performance depends on factors like resource allocation and storage speeds, the latest hardware advances like nested virtualization also mitigate overhead radically. With capabilities like live migration and high availability, virtual machine servers deliver the agility and reliability needed for current dynamic, cloud-focused environments. Continued hypervisor innovations and maturing management tools make it easier than ever to build robust VM server infrastructure tailored to meet business objectives.


  1. What are the differences between virtual servers and dedicated servers?
    Dedicated servers provide exclusive physical resources while virtual servers share underlying physical infrastructure. Dedicated servers offer guaranteed CPU and memory while virtual servers may have noisy neighbors contending for shared resources.
  2. What skills are required to manage virtual servers?
    Hypervisor management, VM monitoring and automation, performance tuning, networking, scripting, troubleshooting and systems administration skills are needed to effectively handle VM server environments.
  3. Can production workloads run reliably on virtual servers?
    Yes, modern hypervisors offer clustering, live migration, fault tolerance and distributed availability capabilities that allow virtual servers to provide the reliability and uptime needed even for business critical production systems if properly configured.
  4. Is virtual server infrastructure secure?
    Hypervisors provide strong isolation between VMs ensuring security. Specific VM configurations are not accessible to others on the same physical server. Securing the hypervisor itself and management network are key to the overall security posture.
  5. How is storage handled on virtual machine servers?
    VM virtual disks representing storage capacity are provisioned from networked storage arrays or internal disks and controllers managed by the hypervisor. Shared storage facilitates automated VM migration between hosts. Hype converged infrastructure combines storage, compute and networking tightly.
  6. What are the scalability limits of virtual servers?
    Scalability depends largely on hypervisor capabilities. Latest hypervisors like vSphere scale to support thousands of VMs on 64 hosts with up to 64TB memory and over 4000 vCPUs. The underlying hardware and storage limits apply along with tested configuration maximums.
  7. Which applications are best suited for virtualized deployment?
    Applications that do not max out server CPU, memory or have specialized hardware needs are well suited. Web servers, application servers, databases, directories, development environments, business applications are commonly virtualized. Newer apps designed cloud-ready work seamlessly.
  8. How does server virtualization impact networking?
    Hypervisors come with extensive virtual switching, routing and firewalling capabilities across VMs. Adapting existing networking models to virtual environment requirements poses challenges like consistent configurations and security paradigms requiring updated skills.
  9. Which is better – hosted shared VM plans or on-premise virtual servers?
    Hosted plans allow getting started faster with less investment while on-premise provides greater control and customization with predictable workloads. Reliability and security requirements, performance needs and business adaptability drive the best choice.
  10. What licensing considerations apply for virtualized workloads?
    Server OS and per processor or core based application licensing models need to adapt to properly account for dynamic scaling and right-sizing in virtual environments. Many ISVs have licensing tailored for virtualization while some restrict virtual deployment.
  11. Can physical and virtual servers co-exist in the same data center?
    Yes, absolutely. Many businesses still run legacy apps on physical servers while modernizing other tiers into virtual. Hypervisors allow mixing virtual with physical servers, storage and networks in the same data center through physical-to-virtual connectivity.
  12. Do Docker containers replace the need for virtual machines?
    Containers and VMs can co-exist with containers providing application level portability while VMs offer full server visualization. Typically containers run inside VMs to maximize resource efficiency and availability while facilitating portability across cloud platforms.
  13. How does desktop virtualization compare with server virtualization?
    Both aim to increase hardware resource utilization but server virtualization enables multiple server instances while desktop virtualization offers one desktop per VM with apps and data centralized allowing access from multiple end user devices to enable mobility and remote working.
  14. What are the disaster recovery considerations for VMs versus physical servers?
    Replication capabilities make restoring server VM backups faster. Support for instant VM recovery and failover across secondary DR sites minimizes downtime risks for virtual servers over physical. Backup scheduling is simpler but underlying storage availability is key.
  15. How can virtual server performance be tracked and benchmarked?
    Hypervisors offer advanced real-time and historical monitoring of VM resource metrics like CPU, memory, disk and network I/O usage along with contention and availability stats. This allows fine-grained tuning and capacity adjustments to reach benchmarks.
  16. Is a SAN necessary for hosting virtual machine disks and data?
    A SAN provides shared block storage with centralized backups, business continuity and disaster recovery capabilities crucial for VMs but comes with cost and complexity. Alternatives like software-defined storage, hype converged platforms and even DAS options may suffice for smaller needs.

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