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

Planning Superdome Conﬁgurations

Rules and Guidelines for Conﬁguring a Complex

Appendix A340

Guidelines for Performance

• If more than one cell in a partition is attached to an I/O chassis,

spread out the I/O devices amongst the cells.

Performance will probably not be as good if all or most I/O operations

go through one cell.

• Do not use the core I/O card as the partition’s main connection to the

network (to your site LAN, for example).

• Within a partition, assign 4X cards evenly across I/O chassis to even

out the bandwidth. See “I/O Cards” on page 317 for more

information.

• Make sure all 4X I/O cards are in 4X slots (see “I/O Cards” on page

317).

• Within an I/O chassis, spread the cards out as evenly as possible.

The System Bus Adapter that connects the chassis to its cell is split

into two halves, one serving each half of the chassis and each with its

own cache, so it is best to distribute the load between the two halves.

Guidelines for Expandability

There is one case in which you may want to consider ordering an I/O

expansion cabinet even if all the I/O chassis inside the CPU cabinet have

not been used up.

Suppose for example you have a CPU cabinet containing a single

partition comprising six cells and using three out of the four possible I/O

chassis inside the CPU cabinet. If the slots in these three chassis are all

used and you need to attach more I/O devices, it may not be a good idea

to begin ﬁlling up the fourth I/O chassis.

If you ever intend to create a new partition using the two remaining cell

slots in this cabinet, you should reserve the fourth I/O chassis for that

partition, so as to meet the high-availability requirement that every

partition in (or beginning in) a CPU cabinet should have a cell attached

to core I/O inside that cabinet.

In this case, you should order an I/O expansion cabinet to accommodate

the I/O needs of the original partition. (I/O expansion cabinets will be

available shortly after the ﬁrst Superdome shipments.)