Oracle Audio Technologies E10898-02 ユーザーズマニュアル

ページ / 88
Managing Domains
Oracle VM Server
2-3
any instruction is executed which would violate the isolation with other guests or 
dom0. In the current implementation, there may be performance penalty for certain 
types of guests and access types, but hardware virtualization also allows many 
Microsoft Windows™ operating systems and legacy operating systems to run 
unmodified.
2.4 Management Domain
Most of the responsibility of hardware detection in a Oracle VM Server environment is 
passed to the management domain, referred to as domain zero (or dom0). The dom0 
kernel is actually a complete Linux kernel with support for a broad array of devices, 
file systems, and software RAID and volume management. In Oracle VM Server, the 
dom0 is tasked with providing access to much of the system hardware, creating, 
destroying and controlling guest operating systems, and presenting those guests with 
a set of common virtual hardware.
2.5 Domains
Domains other than the management domain (dom0) are referred to as domU. These 
domains are unprivileged domains with no direct access to the hardware or device 
drivers. Each domU is started by Oracle VM Server in dom0.
2.6 Hardware Virtualization Vs. Paravirtualization
Oracle VM Server uses paravirtualization, not binary translation. That is, the source 
code of the operating system is modified to support virtualization.
Binary translation is neither faster, nor slower, than hardware virtualization. Whether 
binary translation or hardware virtualization is more efficient than paravirtualization 
depends on the implementation of the binary translation and hardware virtualization, 
and the applications and operating system running as a guest on the system.
Binary translation and hardware virtualization, is required if you are using an 
operating system where it is impractical to do paravirtualization, for example, if the 
source code is not available such as for Microsoft Windows™, or the user base is not 
large enough to sustain a paravirtualization effort such as for the Linux 2.4.x kernel. In 
many situations, paravirtualization may perform better than binary translation as 
operations that cause a hypervisor interaction can be grouped and reused, rather than 
each event requiring its own hypervisor interaction.
2.7 Creating Virtual Machines
Create virtual machines (guests) using the Oracle VM Server virt-install command-line 
tool, or using a Virtual Machine Template in Oracle VM Manager. See 
 and the Oracle VM Manager User’s Guide for more information.
2.8 Managing Domains
Manage domains using the Oracle VM Server xm command-line tool, or using Oracle 
VM Manager. See 
 and the Oracle 
VM Manager User’s Guide for more information.
Migrate domains using the 
xm migrate
 command. Se
 for more information.