Xen Para-Virtualized Drivers - Red Hat ENTERPRISE LINUX 5 - VIRTUALIZATION GUIDE Manual

Chapter 11.

Xen Para-virtualized Drivers

Para-virtualized drivers
guests. Use these drivers if you are using fully virtualized Red Hat Enterprise Linux guests and require
better performance.
Other para-virtualized drivers
There are other para-virtualized drivers for Windows for both Xen and KVM hypervisors.
For Windows guests on Xen hosts, refer to the Windows Para-virtualized Drivers Guide
which covers installation and administration.
For Windows guests on KVM hosts, refer to
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
Architecture support for para-virtualized drivers
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 drivers
bring many of the performance advantages of para-virtualized guest operating systems to unmodified
provide increased performance for fully virtualized Red Hat Enterprise Linux
Chapter 12, KVM Para-virtualized Drivers.
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