Managing Superdome Complexes: A Guide for HP-UX System Administrators

Planning Superdome Conﬁgurations

Building Blocks and Deﬁnitions

Appendix A 309

Crossbar Link to CPU Cabinet Cells are connected to the cabinet by

means of the cell controller's crossbar (XBC) link. A maximum of four

cells plug into a crossbar; there are two crossbar in a CPU cabinet. See

“What is an XBC (Crossbar Controller)?” on page 312 for more

information.

Cell Types

Active Cell An active cell is a cell that has been assigned to a

partition, has power enabled, and is integrated into the operating

system running on the partition.

An inactive cell is a cell that has been assigned to a partition, but was

not activated when the partition booted (either because you de-activated

it by means of its “use on next boot” ﬂag in the complex proﬁle or

because of a failure). An unassigned cell does not currently belong to

any partition.

Base Cell A base cell is a cell that has been assigned to a partition.

Core Cell A core cell (also known as the root cell) is the cell that the

Processor-Dependent Code (PDC) has selected at boot time to perform

the following set of roles and functions for the partition:

• Support the console

• Support the system clock

• Maintain copies of the GSP chassis logs

• Via the monarch CPU, perform the system boot and execute IPL

(Initial Program Load) for the partition.

• Keep the “master copy” for some data structures

• Serve as the criterion for the compatibility of the other cells in the

partition; see“Cell Compatibility” on page 308.

To qualify as a viable core cell, a cell must be a base cell and must be

attached to an I/O chassis that contains a core I/O card. A partition’s

core cell, the one from which it boots, should normally be its

lowest-numbered cell, but partitions can (and, for high-availability

reasons, should) have more than one viable core cell.