Installation guide

Chapter 12. Xen Para-virtualized Drivers
Para-virtualized drivers provide increased performance for fully virtualized Red Hat Enterprise Linux
guests. Use these drivers if you are using fully virtualized Red Hat Enterprise Linux guests and
require better performance.
Note
There are other para-virtualized drivers for Windows for both Xen and KVM hypervisors.
For Windows guests on Xen hosts, see the Red Hat Enterprise Linux 5 Para-virtualized Windows
Drivers Guide, which covers installation and administration.
For Windows guests on KVM hosts, see Chapter 13, KVM Para-virtualized Drivers.
The RPM packages for the para-virtualized drivers include the modules for storage and networking
para-virtualized drivers for the supported Red Hat Enterprise Linux guest operating systems. These
drivers enable high performance throughput of I/O operations in unmodified Red Hat Enterprise
Linux guest operating systems on top of a Red Hat Enterprise Linux 5.1 (or greater) host.
The supported guest operating systems are:
Red Hat Enterprise Linux 3
Red Hat Enterprise Linux 4
Red Hat Enterprise Linux 5
Red Hat Enterprise Linux 6
Note
The minimum guest operating system requirements are architecture dependent. Only x86 and
x86-64 guests are supported.
The drivers are not supported on Red Hat Enterprise Linux guest operating systems prior to Red Hat
Enterprise Linux 3 .
Using Red Hat Enterprise Linux 5 as the virtualization platform allows system administrators to
consolidate Linux and Windows workloads onto newer, more powerful hardware with increased
power and cooling efficiency. Red Hat Enterprise Linux 4 (as of update 6) and Red Hat Enterprise
Linux 5 guest operating systems are aware of the underlying virtualization technology and can
interact with it efficiently using specific interfaces and capabilities. This approach can achieve similar
throughput and performance characteristics compared to running on the bare metal system.
As para-virtualization requires a modified guest operating system, not all operating systems can use
para-virtualization. For operating systems which can not be modified, full virtualization is required.
Full virtualization, by default, uses emulated disk, network, video and other hardware devices.
Emulated I/O devices can be very slow and are not suited for applications requiring high disk and/or
network throughput. The majority of the performance loss with virtualization occurs through the use
of emulated devices.
The para-virtualized device drivers are included in the Red Hat Enterprise Linux packages. The
Red Hat En t erp rise Lin ux 5 Virt ualizat ion Guid e
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