null

VMware

Enterprise Resource Center • Virtualization Knowledge Base

Understanding VMware Virtualization

VMware virtualization allows multiple virtual machines to share the CPU, memory, storage and networking resources of physical servers. Technologies such as VMware ESXi and vSphere have become widely used foundations for consolidating workloads and building virtualized enterprise infrastructure.

VMware ESXi vSphere Virtual Machines Hypervisor
Tech Supply Direct
Quick Answer

What Is VMware?

VMware provides virtualization software that allows multiple virtual machines to run on shared physical server hardware. VMware ESXi is a bare-metal hypervisor installed directly on a server, while VMware vSphere provides a broader virtualization platform for operating and managing virtual infrastructure.

Each virtual machine can be assigned virtual CPUs, memory, storage and network adapters while remaining logically isolated from other virtual machines running on the same physical host.

Virtualization Architecture

Physical Server → ESXi → Virtual Machines

VMware separates applications and operating systems from the physical server hardware by inserting a virtualization layer between them.

LAYER 1

Physical Hardware

Server processors, memory, storage controllers, drives and network adapters provide the underlying compute resources.

LAYER 2

VMware ESXi

The bare-metal hypervisor manages and schedules access to the physical server's CPU, memory, storage and networking resources.

LAYER 3

Virtual Machines

Each VM receives virtual processors, memory, disks and network interfaces from the host.

LAYER 4

Guest Operating Systems

Windows, Linux and other supported guest operating systems run inside the virtual machines.

VMware Fundamentals

Core VMware Components

ESXi Bare-metal hypervisor that runs directly on physical server hardware.
Virtual Machines Software-defined computers with virtual CPUs, memory, disks and network interfaces.
vCenter Centralized management for multiple hosts and virtual infrastructure.
vSphere VMware's broader virtualization platform built around ESXi hosts and centralized infrastructure management.
Benefits

Why Virtualize Servers?

Virtualization can improve hardware utilization while allowing workloads to be managed independently from individual physical servers.

Server Consolidation Multiple workloads can share one physical server instead of requiring dedicated hardware for each application.
Resource Allocation CPU and memory resources can be assigned to individual virtual machines according to workload requirements.
Workload Isolation Multiple operating systems can share a server while remaining logically isolated from one another.
Hardware Flexibility Applications can become less tightly coupled to one specific physical server.
Compute Resources

VMware CPU Considerations

Physical processor resources are exposed to virtual machines as virtual CPUs, commonly called vCPUs. A host may run many vCPUs across multiple virtual machines, but those workloads ultimately compete for the available physical CPU resources.

Physical Cores More physical cores can support greater aggregate compute demand.
vCPU Allocation Assigning unnecessary vCPUs can reduce scheduling efficiency rather than automatically improving performance.
NUMA NUMA topology can become important on multi-socket virtualization hosts. NUMA Guide → Intel Xeon Widely deployed across enterprise virtualization servers. Intel Xeon Guide →
Memory

Memory Is Critical for VMware Hosts

Virtualized servers often require substantial memory because each active virtual machine consumes RAM in addition to the memory required by the hypervisor and supporting services.

Virtual Machine Storage

VMware Storage Performance Matters

A virtualization host may generate I/O from many virtual machines at the same time. Storage latency, IOPS, throughput, redundancy and queue behavior therefore become especially important when sizing VMware infrastructure.

Storage Architecture

What Is a VMware Datastore?

A datastore is a logical storage location used by VMware hosts to store virtual-machine files and other virtualization data. Depending on the environment, datastores may be backed by local storage or shared storage presented through supported storage technologies.

VMFS VMware's clustered filesystem used with block-storage datastores.
NFS Network file storage can also be presented as a VMware datastore.
Local Storage Drives installed directly in a host can provide local datastore capacity where appropriate.
Shared Storage Shared storage enables multiple hosts to access infrastructure required by many clustered features.
Networking

VMware Hosts Depend on Fast, Reliable Networking

Virtualization traffic may include virtual-machine networking, management traffic, storage access, host migration and backup traffic. Network architecture should therefore be sized around the actual workload.

Important

VMware Hardware Compatibility Matters

A component fitting physically into a server does not automatically mean it is appropriate for a VMware deployment. Processor generation, system firmware, storage controllers, network adapters, boot devices and other hardware can affect operating system and hypervisor support.

Compatibility should be validated against the exact server, component, firmware and VMware software version before changing production infrastructure.

Physical Infrastructure

Building a VMware Host

Virtualization performance ultimately depends on the physical infrastructure beneath the hypervisor.

Processors Core count, frequency, NUMA topology and processor generation affect host capacity.
Memory RAM capacity frequently determines how many active virtual machines a server can support.
Storage Latency, IOPS, throughput and redundancy directly affect VM responsiveness.
Networking NIC bandwidth and topology must support guest, management and storage traffic.
Architecture Comparison

Physical Servers vs Virtual Machines

PHYSICAL SERVER
One Workload Per Server Traditional infrastructure may dedicate an operating system and application stack to each physical server.
VIRTUALIZED SERVER
Multiple VMs Per Host A hypervisor allows multiple isolated virtual machines to share the resources of one physical host.
Frequently Asked Questions

VMware FAQ

What is VMware?

VMware provides virtualization technologies that allow multiple virtual machines to share physical server resources.

What is VMware ESXi?

ESXi is a bare-metal hypervisor installed directly on physical server hardware.

What is VMware vSphere?

vSphere is VMware's virtualization platform for operating and managing virtual infrastructure built around ESXi hosts.

What is a virtual machine?

A VM is a software-defined computer with virtual CPU, memory, storage and networking resources.

Does VMware require a specific server?

VMware compatibility depends on the server platform, processor, storage controller, network adapters, firmware and software version being deployed.

How much RAM does a VMware server need?

Memory requirements depend on the number of VMs, memory assigned to each VM, host services and expected workload growth.

Is SSD or NVMe better for VMware?

Faster flash storage can reduce latency and improve IOPS, but the appropriate storage design depends on workload, capacity, redundancy and budget requirements.

Why is NUMA important for VMware?

NUMA topology affects how processors access local and remote memory on multi-socket hosts and can influence large virtual-machine performance.

Enterprise Virtualization Hardware

Upgrading or Building a VMware Server?

Tech Supply Direct can help identify compatible enterprise processors, memory, storage, network adapters and server hardware for VMware virtualization environments based on your platform and configuration requirements.