System information

The virtualization layer schedules the virtual machine operating systems and,
if you are running an ESX host, the service console. The virtualization layer
manages how the operating systems access physical resources. The VMkernel
must have its own drivers to provide access to the physical devices. VMkernel
drivers are modified Linux drivers, even though the VMkernel is not a Linux
variant.
Hardware interface
components
The virtual machine communicates with hardware such as CPU or disk by
using hardware interface components. These components include device
drivers, which enable hardware-specific service delivery while hiding
hardware differences from other parts of the system.
User interface
Administrators can view and manage ESX/ESXi hosts and virtual machines in
several ways:
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A VMware vSphere Client (vSphere Client) can connect directly to the
ESX/ESXi host. This setup is appropriate if your environment has only one
host.
A vSphere Client can also connect to vCenter Server and interact with all
ESX/ESXi hosts that vCenter Server manages.
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The vSphere Web Access Client allows you to perform many management
tasks by using a browser-based interface.
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When you must have command-line access, you can use the VMware
vSphere Command-Line Interface (vSphere CLI).
Software and Hardware Compatibility
In the VMware ESX/ESXi architecture, the operating system of the virtual machine (the guest operating system)
interacts only with the standard, x86-compatible virtual hardware that the virtualization layer presents. This
architecture allows VMware products to support any x86-compatible operating system.
Most applications interact only with the guest operating system, not with the underlying hardware. As a result,
you can run applications on the hardware of your choice if you install a virtual machine with the operating
system that the application requires.
Understanding Virtualization
The VMware virtualization layer is common across VMware desktop products (such as VMware Workstation)
and server products (such as VMware ESX/ESXi). This layer provides a consistent platform for development,
testing, delivery, and support of application workloads.
The virtualization layer is organized as follows:
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Each virtual machine runs its own operating system (the guest operating system) and applications.
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The virtualization layer provides the virtual devices that map to shares of specific physical devices. These
devices include virtualized CPU, memory, I/O buses, network interfaces, storage adapters and devices,
human interface devices, and BIOS.
Fibre Channel SAN Configuration Guide
10 VMware, Inc.