Installation guide

Virtualization is a broad computing term for running software, usually operating systems,
concurrently and isolated from other programs on one system. Most existing implementations of
virtualization use a hypervisor, a software layer that controls hardware and provides guest operating
systems with access to underlying hardware devices. The hypervisor allows multiple operating
systems to run on the same physical system by offering virtualized hardware to a guest operating
system.
5. Types of Virt ualizat ion
5.1. Full Virt ualiz at ion
Red Hat Enterprise Linux contains virtualization packages and tools to run fully virtualized,
unmodified, operating system guests. This provides companies with the ability to consolidate older
systems onto newer, more efficient hardware, and reduces physical space and operating costs
involved with powering and cooling older, less efficient systems. Full virtualization offers lower I/O
performance than native (or bare-metal) installations of operating systems.
5.2. Para-Virt ualiz at ion
Para-virtualization is a virtualization technique which involves running modified versions of
operating systems. The para-virtualized operating system is modified to be aware that it is being
virtualized, offering an increased ability for optimization as the guest is more aware of its
environment. Performance is generally very close to running bare-metal, non-virtualized operating
systems.
5.3. Para-virt ualiz ed drivers
Para-virtualization and full virtualization can be combined to allow unmodified operating systems to
receive near native I/O performance by using para-virtualized drivers on fully virtualized operating
systems.
The para-virtualized drivers contain storage and network device drivers for fully virtualized Microsoft
Windows® guests. The drivers provide Microsoft Windows® guests running on Red Hat Enterprise
Linux with enhanced disk and network I/O performance.
6. How CIOs should t hink about virt ualizat ion
b y Lee Co n g d o n , Ch ief Inf ormat io n O f ficer, Red Hat , In c.
You may already be heavily invested in the rapidly emerging technology of virtualization. If so,
consider some of the ideas below for further exploiting the technology. If not, now is the right time to
get started.
Virtualization provides a set of tools for increasing flexibility and lowering costs, things that are
important in every enterprise and Information Technology organization. Virtualization solutions are
becoming increasingly available and rich in features.
Since virtualization can provide significant benefits to your organization in multiple areas, you
should be establishing pilots, developing expertise and putting virtualization technology to work
now.
Virt u aliz at io n f o r In n o vat io n
Red Hat En t erp rise Lin ux 5 Virt ualizat ion Guid e
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