What is virtual machine and VMware?

A virtual machine is a software-based emulation of a computer system that runs its own operating system and applications like a physical machine. VMware is a company that provides industry-leading software solutions for creating and managing enterprise-grade virtual machines on x86 architecture servers, desktops and laptops.

What is virtual machine and VMware?

Understanding Virtual Machines

A virtual machine is a compute resource that behaves like a physical computer but is built entirely using software abstraction. Key characteristics:

  • Runs a complete operating system and apps like a physical computer system.
  • Shares underlying physical hardware resources allocated by hypervisor.
  • Remains functionally isolated from host and other VMs via encapsulation.
  • Exists as portable software image independent of hardware.
  • Can start, stop, reboot independently without affecting host machine.

So in essence, virtual machines provide the blueprint for delivering full computer systems in software-only form factors.

Key Functions of a Virtual Machine

The core functions of virtual machines include:

  • Enabling consolidation by running multiple VMs on same physical server.
  • Abstracting compute resources from physical limitations.
  • Portability across hosts as software images.
  • Isolation from host and between VMs via encapsulation.
  • Achieving hardware independence for workloads.
  • Simulating customizable virtual hardware environment.
  • Supporting different guest operating systems.
  • Facilitating backup, recovery and migration of entire workloads.

So virtual machines unlock game-changing possibilities for utilizing compute infrastructure efficiently.

Working of a Virtual Machine

A virtual machine works based on these key principles:

  • A hypervisor creates virtualization layer between physical hardware and virtual machines.
  • Hypervisor allocates isolated slice of host resources – CPU, RAM, storage, network to each VM.
  • Guest operating system runs inside VM utilizing allocated resources.
  • Apps execute within guest OS using simulated virtual hardware provided by hypervisor.
  • The VM operating system and apps remain agnostic to actual underlying hardware.
  • VMs act as self-contained execution environments isolated from host and each other.

So the hypervisor manages the mapping of physical resources to multiple virtual machines in a transparent and portable manner.

Types of Virtual Machines

There are two main types of virtual machines:

System Virtual Machines

  • Emulates an entire computer system including virtual BIOS, storage, network adapters etc.
  • Allows installing full guest operating system like Windows, Linux etc.
  • Supports running any applications supported by guest OS.
  • Provides isolation from host system via encapsulation.

Process Virtual Machines

  • Emulates an isolated environment mainly for running specific application processes.
  • Does not emulate hardware or allow full operating system installation.
  • Suitable for executing packaged apps and programming language runtimes in sandbox.
  • More lightweight with faster startup times.
  • Used for testing code and database workflows.

System VMs are most common for infrastructure virtualization while process VMs serve specific computational needs.

Overview of VMware Company

VMware is the pioneer and the market leader in providing virtualization software for building enterprise-grade virtual machines on x86 architecture computers:

  • Founded in 1998 by Diane Greene, Mendel Rosenblum, Scott Devine, Ellen Wang and Edouard Bugnion.
  • Headquartered in Palo Alto, California with R&D centers worldwide.
  • Broad portfolio spanning data center, network, cloud, end-user computing, security and mobility.
  • Flagship offerings include vSphere, ESXi, NSX, vSAN, vRealize Suite etc.
  • Per ENISA, used by over 90% of enterprises in EU and US. 500,000+ global customers.
  • $12+ billion in yearly revenue making it a leader in infrastructure software industry.

So in essence, VMware pioneered x86 server virtualization and remains the dominant player for robust, performance-focused virtual machines.

VMware’s Virtualization Technology

VMware introduced highly advanced and optimized virtualization technology for the x86 industry-standard PC platform:

  • Hypervisor – Provides a layer abstracting physical resources and enabling virtualization.
  • Encapsulation – Isolates VM processes completely from host and each other.
  • Emulated Hardware – Emulates BIOS, graphics, storage, network adapters etc. virtual hardware environment for guest OS.
  • Para-virtualization – Hypervisor provides special APIs for optimized guest OS integration.
  • Live Migration – Seamlessly moves powered-on VMs across physical hosts via vMotion.

So VMware enables creating performant, secure and portable virtual machines taking x86 virtualization to new levels.

VMware Software for Virtual Machines

VMware provides extensive software products for creating and managing virtual machines:

  • vSphere – Industry-leading virtualization platform for virtual machine management.
  • ESXi – Specialized thin hypervisor OS from VMware installed directly on bare-metal.
  • vCenter – Centralized management and automation of VMware virtualized environments.
  • Workstation – Desktop application for running multiple VMs on Windows and Linux PCs.
  • Player – Lightweight desktop VM client allowing usage of precreated VMs.
  • Fusion – Enables running VMs on Mac systems.

So both data center and personal usage of robust virtual machines is comprehensively addressed by VMware’s solutions.

Advantages of VMware Virtual Machines

VMware virtualization offers significant benefits for virtual machines:

  • Server consolidation – Run multiple VMs efficiently sharing underlying host resources.
  • Optimal performance – Hypervisor optimizations and paravirtualization minimize virtualization overhead.
  • Seamless mobility – VMs can migrate across hosts via vMotion with zero downtime.
  • Snapshot backups – Point-in-time VM snapshots allow quick rollbacks.
  • Disaster recovery – VMs easily restored to last known good state after any failures.
  • Scalability – Scale infrastructure up or down by provisioning more VMs instantly.
  • Isolation – VMs provide self-contained secure environments for workload execution.

So VMware unlocks the full potential of virtual machines for performance, availability and stability.

Key Differences – Virtual Machines vs Containers

Though both are virtualization approaches, key differences exist between virtual machines and containers:

Virtual Machines Containers
Emulates full system hardware stack including discrete OS. Share host OS kernel and bins/libs. OS virtualized instead of hardware.
Heavier footprint due to full OS image. Slower boot up. Lightweight as leverage existing OS. Faster startup.
Hypervisor provides encapsulation. Uses native OS process isolation. Additional software adds management layer.
Offers full isolation and security out of the box. Requires tweaking host OS settings for equivalent isolation as VMs.
Hardware-level virtualization built for scalability and resilience. Quick deployment of apps in standardized environments across stacks.
Each VM runs its own dedicated OS instance. Multiple isolated containers share same host OS.

So while VMs provide full system virtualization, containers offer faster, lightweight app and process isolation models.

Key Takeaways

  • Virtual machines emulate computer hardware for flexible deployment of systems as software.
  • VMware pioneered robust virtualization technology allowing efficient usage of x86 servers for virtual machines.
  • VMware’s vSphere and ESXi solutions provide comprehensive capabilities for VM management.
  • Benefits include server consolidation, mobility, scalability and availability of entire workloads.
  • VMs constitute full system virtualization while containers provide lightweight application and process isolation models.

Conclusion

The revolutionary concept of virtual machines enabled computing without tight coupling to physical hardware constraints. This allowed unprecedented consolidation, portability and resilience of workloads. VMware was at the forefront of making enterprise-scale virtual machines on industry-standard x86 servers a practical reality through its advanced hypervisor and management capabilities. By encapsulating entire workloads in secure and mobile VMs abstracted from underlying hardware, VMware unlocked immense potential for efficiency and reliability gains in computing resource usage. VMs underpin the software-defined data center vision and enable cloud computing models. For making robust virtualization universally accessible, VMware continues to lead the way.

FAQs

  1. Is VMware a virtual machine?
    No, VMware is a company providing software for creating and managing virtual machines. The virtual machines themselves constitute abstracted compute environments.
  2. Does virtual machine software require VMware?
    No, alternatives like VirtualBox, QEMU, Hyper-V etc. also allow creating virtual machines. But VMware products are most widely used in enterprises.
  3. Is VMware required for virtualization?
    No, hardware virtualization is a broader concept that can be implemented through other platforms too. But VMware currently leads the industry in providing full-featured virtualization solutions.
  4. What makes VMware virtualization unique?
    VMware spearheaded robust and performant x86 hardware virtualization using techniques like binary translation, paravirtualization, encapsulation etc. giving it a cutting edge over alternatives.
  5. Does virtual machine emulate hardware?
    Yes, virtual machines emulate hardware like CPU, memory, disks, graphics adapter, network cards etc. This provides portability across physical hosts.
  6. Is a hypervisor needed for virtual machine?
    Yes, a hypervisor is required to create the virtualization layer for managing physical host resources used for powering virtual machines.
  7. Is VMware hypervisor a virtual machine?
    The VMware ESXi hypervisor is not itself a virtual machine but a thin operating system running directly on the host hardware to aid virtualization.
  8. Is VMware Type 1 or Type 2 hypervisor?
    VMware ESXi installs directly on the bare-metal host server hardware making it a Type-1 native hypervisor vs Type-2 hosted hypervisors running atop a traditional operating system.
  9. Do you need VMware to create a virtual machine?
    No, virtual machines can be created using other virtualization solutions as well. But VMware products dominate enterprise production deployments currently for robust virtual machine capabilities.
  10. Why are virtual machines important?
    Virtual machines provide benefits like server consolidation, hardware independence, enhanced workload mobility, continuity and scalability making them integral to modern computing environments.
  11. Are containers better than virtual machines?
    Containers provide lightweight application isolation while virtual machines offer full system virtualization. They both have relevant uses cases and pros/cons. Combination is ideal.
  12. How are VMware virtual machines licensed?
    VMware uses a processor/core-based licensing model. Additional capabilities are enabled through higher tiers like Standard, Enterprise Plus. Host-managed licensing available on vCenter.
  13. Does VMware ESXi replace operating system?
    VMware ESXi runs directly on server hardware replacing the need for a traditional operating system to provide base virtualization capabilities.
  14. What are virtual machines used for?
    Virtual machines are used for server consolidation, running multiple operating systems on same hardware, cross-platform application deployment, isolating workloads and for developing, testing, disaster recovery and running legacy apps.
  15. Is VMware only for virtual machines?
    No, while heavily associated with virtual machines, VMware also provides adjacent solutions for networking, storage, cloud management, end-user computing etc. But virtualization remains its core focus.
  16. Does VMware support GPU passthrough?
    Yes, using VMware vGPU technology it is possible to directly assign host system GPU resources to virtual machines and enable GPU acceleration for apps running within VMs.
  17. How does live migration work in VMware?
    Live migration allows moving powered-on VMs across physical hosts without service interruption through VMware vMotion by seamlessly transferring executing state between underlying hypervisors.
  18. Is VMware VM isolation secure?
    Yes, VMware uses advanced techniques like hypervisor-level scheduling controls and memory protections to prevent data leakage across virtual machine boundaries ensuring strong isolation.
  19. Does VMware VM have BIOS?
    The VMware virtualization platform emulates a BIOS environment providing necessary low-level firmware interfaces for booting up and running complex operating systems like Windows within virtual machines.
  20. What is difference between VMware and vSphere?
    VMware is the company name while vSphere is their specific product suite for data center and cloud virtualization focused on compute, network and storage virtualization capabilities.

Leave a Comment