Solaris 10 Container Virtualization Primer: One of the key breakthrough technologies in Solaris 10, Solaris Container has the ability to promote server consolidation, as well as improve application availability and manageability. In this interview, Inner Circle plays 20-plus questions with Sun virtualization experts Joost Pronk van Hoogeveen, Jeff Victor, and Chien-Hua Yen to more fully understand the potential, capabilities, and limitations of Solaris Containers and Solaris Zones.

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One of the key breakthrough technologies in Solaris 10, Solaris Container has the ability to promote server consolidation, as well as improve application availability and manageability. In this interview, Inner Circle plays 20-plus questions with Sun virtualization experts Joost Pronk van Hoogeveen, Jeff Victor, and Chien-Hua Yen to more fully understand the potential, capabilities, and limitations of Solaris Containers and Solaris Zones.

IC: What are the differences among Logical Domains, Solaris Zones, and Solaris Containers?

Joost Pronk van Hoogeveen: Domains are a type of hardware partitioning, so the partitioning is done at the hardware level. Solaris Zones are part of Solaris Containers technology. As such, Zones manage the namespace isolation (separate IP addresses and users, for example) for Containers. Containers and Zones are a type of operating system virtualization, where the partitioning is not done at the hardware level, but rather within the operating system itself.

IC: Are Zones and Containers the same thing?

Jeff Victor Not exactly. The official definition for a Solaris 10 Container is a Solaris Zone using resource management features. But in casual conversation, few people distinguish between Zones and Containers.

IC: Aside from Zones, what else comprises Solaris Containers?

Joost Pronk van Hoogeveen: Solaris Containers are made up of two major components: Solaris Zones and Solaris Resource Manager (SRM). SRM manages the physical system resources every Container receives, and Solaris Zones control the namespace isolation. Together, Zones and SRM form the basis for Solaris Containers.

IC: What distinguishes Solaris Containers from virtual domain technologies, such as LPARs?

Joost Pronk van Hoogeveen LPARs are a typical virtual machine technology with a hypervisor layer between the hardware and the operating system, whereas Solaris Containers are a type of operating system virtualization. Virtual domains and virtual machines allow different types of operating systems to be run concurrently on the same physical machine. But, as with all virtual machine technologies, there is significant performance overhead to this approach. By contrast, Solaris Containers are very lightweight and create hardly any performance overhead. But Solaris Containers permit only a single operating system version.