Supporting Software - Expert Consolidation in Oracle Database 12c - page 113

An Introduction to Solaris Zones
Solaris zones have been the weapon of choice for Solaris virtualization, especially on non-SPARC servers where
Logical Domains are not available. A first massive wave of consolidation rolled through data centers some years
ago, after zones where first introduced. The zone concept is very compelling, elegant, and simple. Instead of having
powerful servers sitting idly most of the time when there are no development or test activities, many of these
environments could be consolidated into one server. In addition, a zone isolates applications in a way that even
root-owned processes in zone1 cannot view processes in zone2 . Block level replication on the array level allows for
very simple yet effective disaster recovery solutions. As you will, each zone has its own root directory that can reside
on block-replicated storage. Application-specific file systems can equally be storage-replicated. Before starting with a
discussion of how to set up a zone, a little bit of terminology is explained in Table 4-1 .

Table 4-1. Necessary Terminology for Solaris Zones
Concept Explanation

IPS The Image Packaging System is a framework for managing software in Solaris 11. It replaces

the System V Release 4 package management system used in previous versions of Solaris.
The SysVR4 package management system is still available for backward compatibility.
So, instead of pkgadd, you will from now on have to get familiar with the pkg command
and its many options.

ZFS ZFS is the next generation Solaris file system and supplements UFS in Solaris. It has

many advanced features, such as volume management, high storage capacity, integration
checking, copy-on-write clones, Access Control Lists, and many more built-in. In ZFS, you
aggregate disks or LUNs into storage pools. The storage pool is conceptually similar to
the Linux LVM2 volume group. It can be configured as a striped set of LUNs, or a (RAID 1)
mirror, or, alternatively, as a RAIDZ, which is similar to RAID 5.

You create the actual ZFS file systems on top of the storage pool. It is strongly encouraged
to create hierarchies of ZFS file systems, grouping similar file systems under a common top
level container. The concept behind this hierarchy is very elegant. ZFS file systems inherit
metadata properties from their parent container, such as mount points, quotas, caches,
and so on.
A ZFS dataset is a generic name for a clone, an actual file system, or a snapshot. In the
context of zones, a dataset is most often a file system.

Global Zone The initial zone after the operating system has been installed.

Non-Global Zone Non-global zones are user defined containers, similar in concept to virtual machines, as

known from desktop virtualization products.

Zones can have multiple lifecycle states. The important ones from a DBA point of view are “installed” and
“running.” A zone with the status “installed” is shut down, waiting to be started. The other states are of more interest
to the system administrator who creates the zone.
Storage for Solaris zones merits a closer look. For mid- and higher-tier systems (user acceptance testing,
production of course), it makes sense to think in terms of disaster recovery, and this is where the isolation aspect of
the zones really shines.

■ Note By the way, you can apply the same principle subsequently shown to almost any virtualization technology.