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

Configuring and Managing Superdome Partitions
Configuring Superdome Hardware and Partitions
Chapter 4 125
Partition Configuration Guidelines
HP offers the following general partition configuration guidelines in
addition to the hardware prerequisites listed in the previous section.
These guidelines are incorporated in the procedure that follows
(“Procedure for Assigning Cells to Partitions” on page 126).
Use these guidelines to help determine which cells to assign to the
partitions you create.
• Allocate partitions in order of size.
Assign cells to the partition that has the largest cell count first, and
the partition with the fewest cells last.
This provides more appropriate cell assignments for larger partitions
(those with more cells). Any smaller partitions with fewer cells are
more easily accommodated in the remaining, available cells.
• Place each partition within an empty cabinet, if possible.
This applies to partitions in Superdome 64-way systems only.
Assign the partition cells from a cabinet whose cells have no partition
assignments, if possible. Do this before assigning cells from a cabinet
that already has cells assigned to another partition. Doing so can help
minimize contentions for using cabinet backplane connections.
• Assign each partition cells from an unused “cell quad”, if
possible.
Each “cell quad” is a set of four cells that share the same cabinet
backplane connections (crossbar chips). Cell slots 0–3 comprise one
cell quad, and cell slots 4–7 comprise the second cell quad.
Cells that share the same crossbar chips (cabinet backplane
connections) have the best cross-cell memory performance.
Partitions with cells on different crossbar chips have higher memory
latency (worse memory performance) than partitions whose cells all
share the same crossbar chip. This applies to partitions that have all
cells in the same cabinet and to partitions that include cells in
different cabinets.