Recently thereís been a lot of news about OpenSolaris, more
specifically in reference to the great progress made by virtualization
technologies in it. In this article, I will exam some of these
technologies, and compare them with the state of the art on other
OpenSolarisí Zones is a mechanism that provides isolated
environments with a subset of the host operating systemís privileges,
allowing applications to run within the zone without any modifications
(Xen is also capable of this). This makes zones useful for server
consolidation, load balancing and much more.
Each zone has a numeric ID and a unique name; the global zone has ID
0, is always running and cannot be halted. There are two user space
tools for zone configuration, creation and management:
zoneadm; these tools use a lightweight IPC (Inter Process Communication) mechanism called doors to communicate with the kernel, which is implemented as a virtual file system (
doorfs). When using doors, context switches are executed using a unique synchronization mechanism called shuttle, instead of through the kernel dispatcher; this allows faster transfer of control between kernel threads.