36 IBM N etfinity EXP3 00 - Type 3531 Hardware Main tenance Man ual
2. Install the expansion unit ID label.
a. Verify the setting of the expansion unit number swit ch (0-9).
b. Apply the expansion unit ID label that matches the setting for the unit ID
switch in the blank label area directly to the left of the SCSI ID label.
3. Continue with “Cabling the expansion unit”.
Cabling the expansion unit
This section provides the SCSI and power cabling info rmation. After you attach your
SCSI and power cables, use the instructions provided in “Turning the expansion unit
on and off” on page 3 for the initial start u p of the expansion unit.
SCSI cabling information: The IBM Netfinity EXP300 comes with two ESM boards.
There are two 68-pin SCSI Very High Density Connector Interface (VHDCI)
connectors. From le ft to right as seen from t he back, these conne ctors are for SCSI bu s
2 and SCSI bus 1. (See “Rear controls, indicators, and connectors” on page 15 for the
location of these connectors.) There are three ways to configure these buses.
Attention: A loss of data can occur if you change the position of internal switch 1 or
internal switch 3 after s toring data on the drives. Refer to “Conversion of EXP300 to a
tower or from a tower” on page 25 if y ou pr ev iousl y st ored data o n t he dri ves and you
now want to change the co nf i gu ration of your expans io n unit from a rack to a tower
orientation.
• To configure each bus independently:
1. Verify that op tion sw itch 3 (i nsid e the switc h card) is set to On. (See “Setting
the interface options and ID settings” on page 10 for more information.)
2. Attach one external SCSI cable from the controller in the server to the SCSI-
bus 1 connector.
3. Attach a second external SCSI cable from the controller in the server to the
SCSI-bus 2 connector.
• To configure the expansion unit as a single 14-drive SCSI bus:
1. Verify that Opt ion Switch 3 (inside the switch card) is set to Off. (See
“Setting the interface options and ID settings” on page 10 for more
information.)
2. Attach one external SCSI cable from the controller in the server to either
SCSI-bus connector.
• To configure the expansion unit as a cluster of 13 drives on a single SCSI bus
when using IBM ServeRAID controllers:
Note: When clustering wit h IB M S e rv eRAID adapters, you mu s t con figure all
13 disk drives on a single SCSI bus. The drive bay with SCSI ID=6 is
automatically disabled to avoi d an ID conflict with one of the
ServeRAID controlle rs.
1. Verify that inte rnal option switch 3 is set to Off. (See “Setting the interface
options and ID settings” on page 10 for more information.)
2. Attach one external SCSI cable from the controller in server 1 to the SCSI-
bus 1 connector.
3. Verify that the drive bay with SCSI ID=6 contains a filler panel.
4. Verify that one of the ServeRAID controllers is set to SCSI I D=6.
5. Attach a second external SCSI cable from the controller in server 2 to the
SCSI-bus 2 connector.