Supporting Software - Expert Consolidation in Oracle Database 12c - page 112

does not normally need to know (or care) about what data it is shipping. This is an advantage and disadvantage.
If done properly, block replication can be the one ticket to happiness when you replicate your entire application
stack: application servers, database servers, and other auxiliary components. Then, all you need to do is mount your
replicated storage in your DR data center and bring your systems up. Clever management of your corporate Domain
Name System can make it simple to swap the old with the new IP addresses.

Virtualization Examples
The next sections are intended to show you some examples for virtualization technologies. The technologies are
chosen to provide you an overview of what is possible on different platforms. The selection is by far not complete!
The market leader in virtualization—VMware—for example, is not included in the list. It simply does not need to be
introduced anymore.
The first technology presented is Oracle Solaris Zones. Zones are examples for operating system virtualization.
One image of the operating system is the basis for multiple isolated copies of the same, operating in complete
independence. Solaris is available for x86- and SPARC-based systems. Linux Kernel Virtual Machines are conceptually
similar, as to an extent IBM's Logical Partitions.
Following the introduction of Oracle Solaris Zones, you are shown another popular x86-virtualization technology
based on a so called bare-metal hypervisor: Oracle VM Server for x86. With Oracle VM, you boot into a very
minimalistic operating system that runs directly on the “bare” hardware and provides all access to the hardware for
virtual machines.

■ non-enterprise or desktop virtualization products are not covered in this chapter. they are aimed at end-users
to run operating systems in isolation on their desktops, not at data centers.

Note

Let me stress again that the selection of examples is neither exhaustive nor provides the relevant selection of
virtualization technologies. All of them serve a purpose, and the listing here does not imply a ranking or measure of
quality. Let's start the discussion with an overview of Oracle Solaris Zones.

Oracle Solaris Zones
Solaris zones are an example for operating system virtualization. A Solaris system-x86 and SPARC alike can be
subdivided into logical units called zones. Another name for a zone is a container, and the two terms are often used
synonymously. The use of Solaris zones is a very easy and attractive way to make use of a large server that offers plenty
of resources. A zone is an isolated environment and, in many respects, resembles a virtual machine from desktop
virtualization products, although its management requires experience with the command line.
When you install Solaris 10 or 11, you automatically find one zone already created: the so-called global zone.
It is then up to you to create additional zones, referred to as “non-global zones.” This section uses the simpler term
“zone” instead when referring to non-global zones. Just like with Oracle 12c you have the option to not use zones at all
in which case your software will be installed in the global zone. You should, however, consider creating a non-global
zone to install your software in. This can make many tasks a lot easier.
In most cases, a zone runs a version of Solaris—the same as the global zone. Recent versions of Solaris support
what is termed a Branded Zone . A Branded Zone or BrandZ allows you to run Solaris 8, Solaris 9, and Red Hat
Enterprise Linux 3, in addition to Solaris 10. Solaris 11 has reduced the number of supported brands to Solaris 10
only in addition to Solaris 11. The idea of using a Branded Zone is to allow the user to migrate to Solaris 10 but keep
applications that cannot possibly be ported to the current Solaris release.