Solaris zones is a major new feature of Solaris 10 and provides additional facilities that were not available in previous releases of the Operating Environment. Zones allow virtual environments to run on the same physical system. Previously, the only way of compartmenting an environment was to purchase a separate server, or use an expensive high-end server, capable of physical partitioning, such as the E10K or E15K. Now you can create virtual environments on any machine capable of running the Solaris 10 Operating Environment.
Zones provide a virtual operating system environment within a single physical instance of Solaris 10. Applications can run in an isolated, and secure environment. This isolation prevents an application running in one zone from monitoring or affecting an application running in a different zone. A further important aspect of zones is that a failing application, such as one that would traditionally have leaked all available memory, or exhausted all CPU resources, can be limited to only affect the zone in which it is running. This is achieved by limiting the amount of physical resources on the system that the zone can use.
This chapter looks at the whole concept of Solaris zones and how to configure and create a zone, make it operational, and then remove it. Resource management is not an objective for exam 310-202, but a brief introduction is included in this chapter to help put the zones feature in the correct context.
Zones and Containers Some refer to zones and containers interchangeably as if they mean exactly the same thing. This is incorrect because containers is a technology that comprises the resource management features, such as resource pools and Solaris zones. Solaris zones is a subset of containers, so the two terms should not be used interchangeably.