Oracle Solaris Zones is a virtualization technology that enables you to consolidate multiple physical machines and services on a single system. Virtualization reduces costs through the sharing of hardware, infrastructure, and administration. Benefits include the following:
Increased hardware utilization
Greater flexibility in resource allocation
Reduced power requirements
Fewer management costs
Lower cost of ownership
Administrative and resource boundaries between applications on a system
The Oracle Solaris Zones partitioning technology is used to virtually divide the resources of a physical machine and its Oracle Solaris operating system operating system to simulate multiple machines and operating systems. Each virtual system that is created in a zone is dedicated to the programs running inside. Zones technology is used to provide an isolated and secure environment for running applications.
Oracle Solaris Zones provides two main types of zones, each having attributes that control how its operating system behaves and how it can be used.
The instance of the operating system that is running directly on a system is called the global zone.
An instance of a virtual system running inside the global zone is called a non-global zone, or simply a zone.
A kernel zone is a non-global zone that runs a kernel and operating system that is separate from the global zone. The separate kernel and operating system installation in a kernel zone provide for greater independence and enhanced security of operating system instances and applications. Oracle Solaris Kernel Zones can run an Oracle Solaris release, Support Repository Update (SRU), or kernel version that is different from that of the host system. The Oracle Solaris release in a kernel zone must be at least Oracle Solaris 11.2.
Every zone is configured with an associated brand. The brand is used to determine behavior when a zone is installed and booted. In addition, a zone's brand is used to identify the correct application type at application launch time. The default brand is solaris. The brand for a kernel zone is solaris-kz. The brand for a zone running Oracle Solaris 10 is solaris10.
When you create a zone, you produce an application execution environment in which processes are isolated from the rest of the system. This isolation prevents processes that are running in one zone from monitoring or affecting processes that are running in other zones. Even a process running with root credentials cannot view or affect activity in other zones. Use Oracle Solaris Zones to maintain the deployment model of one-application-per-server while simultaneously sharing hardware resources.
A zone also provides an abstract layer that separates applications from the physical attributes of the system on which they are deployed. Examples of these attributes include physical device paths.
Zones can be used on any system that is running at least the Oracle Solaris 10 release. The upper limit for the number of solaris, solaris10, and solaris-kz zones on a system is 8192. The number of zones that can be effectively hosted on a single system is determined by the total resource requirements of the application software running in all of the zones, and the size of the system.
System requirement concepts for Oracle Solaris Zones are discussed in Chapter 1, Before You Begin Working With Oracle Solaris Zones in Creating and Using Oracle Solaris Zones.
System requirement concepts for Oracle Solaris Kernel Zones are discussed in Software and Hardware Requirements for Oracle Solaris Kernel Zones in Creating and Using Oracle Solaris Kernel Zones.