Buying A Support Subscription - Novell LINUX ENTERPRISE SERVER 11 - VIRTUALIZATION Manual

tion platform and expect to interact directly with the hardware. Because this is not
possible when consolidating servers, the hardware must be emulated for the operating
system. Emulation can be slow, but it is especially troubling for high-throughput disk
and network subsystems. Most performance loss occurs in this area.
The device drivers in SUSE Linux Enterprise Virtual Machine Driver Pack bring many
of the performance advantages of paravirtualized operating systems to unmodified op-
erating systems because only the paravirtualized device driver (not the rest of the oper-
ating system) is aware of the virtualization platform. For example, a paravirtualized
disk device driver appears as a normal, physical disk to the operating system. However,
the device driver interacts directly with the virtualization platform (with no emulation)
to efficiently deliver disk access, allowing the disk and network subsystems to operate
at near native speeds in a virtualized environment, without requiring changes to existing
operating systems.
TIP: Best Practices
Before installing SUSE Linux Enterprise Virtual Machine Driver Pack in your
production environment, we strongly recommend that you run it in a test en-
vironment to ensure that it functions properly with your system.

8.1 Buying a Support Subscription

The customer support you receive for the SUSE Linux Enterprise Virtual Machine
Driver Pack is at the same level as your SUSE Linux Enterprise support subscription
[http://support.novell.com/linux/sles_support.html]. You can
choose the following levels of support:
• Basic
• Standard
• Priority
Descriptions of these levels of support and how to buy them are found at SUSE Linux
Enterprise Server 11 How to Buy
server/howtobuy.html].
86 Virtualization with Xen
[http://www.novell.com/products/