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Chapter 3. Installing multiple storage systems on a SCSI bus
3 Installing multiple storage systems on
a SCSI bus
Read this chapter if you are either installing two or more storage systems on the same
SCSI bus.
The procedures in this chapter assume the following:
D
The installation site meets the ac power requirements and operating limits listed
in Appendix A.
D
You have all the cables and cable adapters that you need (see Appendix B).
D
Someone has installed the SCSI-2 adapter in the server, and if necessary, updated
the server’s driver software for the adapter. Refer to the server’s documentation
for information on installing the adapter.
D
If the SCSI-2 adapter provides a single-ended bus, someone has connected a
single-ended to differential converter to the adapter to provide a differential SCSI
bus to the storage system.
Attaching the slot matrix diagram
Three sticky-backed labels are shipped with the storage system: a slot matrix showing
the disk drive module locations, and two sheets of stickers for identifying disk
modules. Attach the slot matrix label to your storage-system cabinet so it is visible.
Save the two sheets of stickers for the person configuring the disk modules into
logical units (LUNs).
SCSI-2 bus length
The total length of the SCSI-2 bus must not exceed 25 meters (81 feet), including all
external and internal SCSI bus cables for the server.
IMPORTANT The length of the internal SCSI bus in the storage system is
effectively zero.
"
To calculate the length of the SCSI bus for your storage system configuration, add the
following:
For multiple storage systems connected to one server on the same bus
D
Length of the server’s internal SCSI bus (refer to the documentation for the
server).
D
Length of the SCSI bus cable between the server and the first storage system. If
you are using a single-ended-to-differential SCSI bus converter between the
server and the first storage system, you must include the lengths of the cables
between the server and the converter and the converter and the storage system.