IBM DS3950, Installation, User'S, And Maintenance Manual, Page: 74 / 252

Fibre Channel loop and ID settings
When you install a hard disk drive in the storage subsystem, the drive tray plugs
into a printed circuit board called the
midplane . The midplane sets the Fibre
Channel loop ID automatically, based on the enclosure ID switch setting and the
physical location (bay) of the hard disk drive.
Working with SFPs and fiber-optic cables
Each RAID controller has up to four single-ported host channel connections
(depending on the configuration you ordered) and two dual-ported drive channel
connections. A Small Form-factor Pluggable transceiver (SFP) connects each host
channel port and drive channel port to hosts and storage expansion enclosures.
Notes:
1. IBM SFP options have been tested and approved for the IBM DS storage
products. For optimal performance and compatibility, always use IBM SFP
options when installing the IBM DS products.
2. The SFPs are preinstalled in the DS3950.
The SFP is inserted into the port, and then a fiber-optic cable is inserted into the
SFP. The other end of the fiber-optic cable connects to an external device. SFPs are
laser products.
Enclosure ID
Enclosure ID
Figure 23. Storage subsystem seven-segment enclosure IDs
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IBM System Storage DS3950 Storage Subsystem: Installation, User’s, and Maintenance Guide