IBM EXN1000, Hardware And Service Manual, Page: 38 / 94

Attention: Verify that all shelf IDs are correct and sequential in the
individual loop(s). If this system was configured by manufacturing, there are
labels on the outside of the packaging carton and on the side of the expansion
unit chassis to indicate which loop on which node (Filer 1 or 2) that shelf
should be located. Make certain the expansion units are placed and cabled
according to these labels. The filer nodes may also have a label on the
packaging carton and chassis side to clearly distinguish the nodes (Filer 1 and
Filer 2).
EXN1000 expansion unit numbering
Each EXN1000 expansion unit in a loop must have a unique ID. A valid shelf
ID is from 1 through 7. ID 1 is used for the first EXN1000 in a new loop, or if
the filer also contains disks, then ID 2 is used for the EXN1000 closest to the
N series storage system controller (which uses ID 1). Shelf IDs for additional
expansion units are incremented sequentially from the number of the first
expansion unit (either 1 or 2).
Each EXN1000 expansion unit shipped with an N series storage system has its
assigned ID already set on its back panel and has a shelf ID label already
placed on its front bezel.
You must ensure that the EXN1000 expansion unit has the correct shelf ID
number on the label. If you change the shelf ID of the expansion unit by
changing the ID switch at the rear of the unit, replace the shelf ID label to
match the new shelf ID for the unit.
Note: Additional shelf ID labels are supplied with your unit.
The shelf ID label is on the right side of the unit, as shown in the following
illustration.
4 5 6 7 8 9 10 11 12 13 3 2 1 0
Drive Bays
Shelf 1
0 13
Loop ID
29 - 16
Figure 1. Shelf ID label
8