Oracle X6-2-HA Deployment And User's Manual page 167

within its own domain. A virtual machine is granted virtual resources, and can be
started, stopped, and restarted independently.
Virtual Disks
In addition to virtual machines, you can create virtual disks in shared repositories.
Virtual disks provide additional storage options for virtual machines by enabling you to
attach additional block storage to your virtual machines. Similarly, you can detach the
storage if you no longer need the additional space. You can use virtual disks to
expand existing file system storage inside the virtual machine by extending the storage
volume onto a virtual disk, or by creating a new file system on a virtual disk. Your
virtual disks can also share multiple virtual machines running on the same shared
repository.
A driver domain is a user domain that has special privileges and responsibilities for a
particular piece of hardware. When you use the driver domain option, the newly
created virtual disks are mounted directly from ODA_BASE to a guest virtual machine.
The option improves performance by enabling guest virtual machines to use ODA_BASE
instead of Dom0 to access virtual disks. The driver domain option is available beginning
with release 12.1.2.7.0 and is supported with Oracle Linux, Windows, and Oracle
Solaris x86 guest operating systems. Live migration of driver domain virtual machines
is not supported.
Shared Repositories
A shared repository is a central location for storing resources that are essential to
creating and managing virtual machines. These resources include virtual machine
templates and assemblies, ISO files (virtual DVD images), virtual machine
configuration files, and virtual disks. Shared repositories are configured on an Oracle
Automatic Storage Management Cluster File System (Oracle ACFS) and then
presented to the Oracle Database Appliance nodes that need access to those
resources. Oracle Database Appliance Virtualized Platform uses shared repositories to
optimize available disk space usage in the environment, and for easy reallocation of
virtual machines if a physical server fails. The virtual machine files can be stored on
shared disks, providing shared storage for the virtual machines. Additionally, you can
configure CPU pools and a resizeable Oracle Database domain (ODA_BASE) to
ensure that the virtual machines do not consume cycles from each other or from your
assigned database CPU cores.
• The shared disks on Oracle Database Appliance Virtualized Platform are
connected directly to ODA_BASE.
• ODA_BASE contains three shared repositories named fs1, fs2, and fs3.
• Each shared repository is an Oracle ACFS in ODA_BASE created on top of the
Oracle Automatic Storage Management (Oracle ASM) disk group (DATA or
RECO) chosen by the user when creating the shared repository.
• The process that creates a shared repository also performs a network file system
(NFS) export of the shared repository to the respective Dom0 by using the private
network.
• The export enables shared storage for the virtual machine files.
Oracle Database Appliance Virtualized Platform Architecture
Chapter 12
12-5