NonStop S-Series Server Description Manual (G06.24+)

Introduction

HP NonStop S-Series Server Description Manual—520331-003

1-24

Maximum I/O for a Single Processor Enclosure

If ServerNet adapters are excluded from the processor enclosures, two additional

ServerNet expansion boards can be installed, one for the X fabric and one for the Y

fabric. As shown in Figure 1-13, these additional SEBs increase the number of I/O

enclosures that can be supported from two to five.

In comparison with Figure 1-12, note that the processor enclosure still has the four

ServerNet addressable controllers (SACs) for internal I/O. However, the processor

enclosure now has four SEBs instead of two, and no ServerNet adapters.

The added SEBs (lower row of SEBs across the diagram) have five links available for

I/O enclosure connection, whereas the original SEBs (upper row) have no links for I/O

enclosures. When dual SEBs are present, their functions are separately defined. One

pair of SEBs is used strictly for connection to other processor enclosures, and the

other pair is used strictly for connection to I/O enclosures.

In Figure 1-13, some ServerNet links have been grouped together for drawing

convenience. Such groups of links should be understood to be electrically and

physically separate. Bold lines are used to represent the fact that several links are

present. A slash through the bold line and an accompanying numeral designate the

number of links. A black triangle shows the starting point of such groupings.