Installation guide

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Glossary
This glossary is intended to define the terms used in this Installation Guide.
Bare-metal The term bare-metal refers to the underlying physical architecture of a
computer. Running an operating system on bare-metal is another way
of referring to running an unmodified version of the operating system
on the physical hardware. An example of operating system running on
bare metal is a normally installed operating system.
Full virtualization KVM uses full, hardware-assisted virtualization. Full virtualization
uses hardware features of the processor to provide total abstraction
of the underlying physical system (Bare-metal) and creates a new
virtual machine in which the guest operating systems can run. No
modifications are needed in the guest operating system. The guest
operating system and any applications on the guest are not aware
of the virtualized environment and run normally. Para-virtualization
requires a modified version of the Linux operating system.
Fully virtualized See Full virtualization.
Guest system Also known as guests, virtual machines, virtual servers or domains.
Hardware Virtual Machine See Full virtualization
Host The host operating system runs virtualized guests.
Hypervisor The hypervisor is the software layer that abstracts the hardware from
the operating system permitting multiple operating systems to run on
the same hardware. The hypervisor runs on a host operating system
allowing other virtualized operating systems to run on the host's
hardware.
The Kernel-based Virtual Machine hypervisor is provided with Red
Hat Enterprise Linux.
I/O Short for input/output (pronounced "eye-oh"). The term I/O describes
any program, operation or device that transfers data to or from a
computer and to or from a peripheral device. Every transfer is an
output from one device and an input into another. Devices such as
keyboards and mouses are input-only devices while devices such as
printers are output-only. A writable CD-ROM is both an input and an
output device.
Kernel SamePage Merging Kernel SamePage Merging (KSM) is used by the KVM hypervisor
to allow KVM guests to share identical memory pages. The pages
shared are usually common libraries or other identical, high-use data.
KSM allows for greater guest density of identical or similar guest
operating systems by avoiding memory duplication.
For information on using KSM with Red Hat Enterprise Linux refer to
Chapter 21, KSM.
Kernel-based Virtual
Machine
KVM (Kernel-based Virtual Machine) is a Full virtualization solution
for Linux on AMD64 and Intel 64 hardware. KVM is a Linux kernel
module built for the standard Red Hat Enterprise Linux kernel. KVM