Domains and System Boards

A domain is an independent system resource that runs its own copy of the Solaris OS. Domains divide a system’s total resources into separate units that are not affected by each other’s operations. Domains can be used for different types of processing; for example, one domain can be used to test new applications, while another domain can be used for production purposes.

The number of physical system boards in your server varies from 1 to 16, depending on whether you have a midrange or a high-end server. One physical system board (PSB) consists of 4 CPUs, 32 dual inline memory modules (DIMMs), and I/O. The I/O varies with the server, and can include PCIe slots, PCI-X slots, and built-in I/O.

To use a PSB in your system, the hardware resources on the board must be logically divided and reconfigured as eXtended System Boards (XSBs). There are two modes of XSBs:

■Uni-XSB

■A PSB logically undivided and configured into one XSB

■Contains all the resources on the board: 4 CPUs, 32 DIMMs, and I/O

FIGURE 4-1shows a PSB in Uni-XSB mode on a midrange server, and FIGURE 4-2shows a PSB in Uni-XSB mode on a high-end server. The CPU modules and memory modules are known as the CPU/memory board unit (CMU) and the I/O devices are contained in the I/O unit (IOU).

48 SPARC Enterprise Mx000 Servers Administration Guide • November 2007