•
Oracle Database Appliance Base Domain (ODA_BASE): A privileged virtual
machine domain, specifically for databases, that provides database performance
similar to bare metal deployments. A PCI pass-through driver provides
ODA_BASE direct access to the shared storage.
•
Domain 0 (Dom0): Default domain that initiates Oracle Database Appliance
Virtualized Platform provisioning processes and hosts virtual machine templates.
Most of the responsibility of hardware detection in an Oracle Database Appliance
Virtualized Platform environment is passed to the management domain, referred to
as domain zero (or Dom0). On x86-based servers, the Dom0 kernel is actually a
small-footprint Linux kernel with support for a broad array of devices, file systems,
and software RAID and volume management. In Oracle Database Appliance
Virtualized Platform, Dom0 provides access to much of the system hardware,
creating, deleting and controlling guest operating systems, and presenting those
guests with a set of common virtual hardware.
•
Guest Domains (Domain U): Virtual machines that are provisioned to host non-
database workloads, such as applications and middleware. Guest operating
systems each have their own management domain, called a user domain,
abbreviated to "Domain U". These domains are unprivileged domains that have no
direct access to the hardware or to the device drivers. Each Domain U starts after
Dom0
is running on Oracle Database Appliance Virtualized Platform.
About Virtual Machines and Oracle Database Appliance Virtualized
Platforms
Oracle Database Appliance Virtualized Platform is designed to run and deploy virtual
machines to manage system resources.
Configure virtual machines on Oracle Database Appliance Virtualized Platform to
manage your application use of shared repository resources, such as the CPU pool,
memory, and other shared resources.
Virtual Machine Templates
Virtual machines can be created from a template or assembly containing
preconfigured virtual machines. The creation of a virtual machine from a template is
based on cloning: the template is imported as an archive, unpacked, and stored as a
virtual machine configuration file with disk images. These disk images are cloned to
create a new instance in the form of a virtual machine. In the same way, an existing
virtual machine can be cloned to create a new virtual machine, or cloned to create a
new template.
Virtual Machine Assemblies
Virtual machine assemblies are often described as a template of a group of virtual
machines, or a collection of virtual machine templates. An assembly can contain a
single virtual machine or a collection of virtual machine templates.
Domains, Guests and Virtual Machines
The terms domain, guest, and virtual machine are often used interchangeably, but
they have subtle differences. A domain is a configurable set of resources, including
memory, virtual CPUs, network devices, and disk devices, in which virtual machines
run. A guest is a virtualized operating system running within a domain. Multiple guests
can run on the same instance of Oracle Database Appliance Virtualized Platform, each
Chapter 12
Oracle Database Appliance Virtualized Platform Architecture
12-4
Summary of Contents for Database Appliance X6-2-HA
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