Fibre channel loop and ID settings
When you install a hard disk drive in the storage expansion enclosure, 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 setting and the
physical location (bay) of the hard disk drive.
Cabling the EXP395
The storage expansion enclosure supports two redundant drive loops. A redundant
storage expansion enclosure drive loop consists of one or more storage expansion
enclosures that are connected to a storage subsystem using two sets of
fibre-channel cables. If one fibre-channel drive loop fails, the storage subsystem
uses the other drive loop to maintain input/output (I/O) to the storage expansion
enclosure drives. Usually, there are two redundant array of independent disks
(RAID) controllers in a storage subsystem. Use the
Installation, User's and
Maintenance Guide
or
System Storage Quick Start Guide
that ships with your storage
subsystem for the specific information about cabling the storage expansion
enclosure to a storage subsystem. Before cabling the storage expansion enclosure,
read the following information:
v
Fibre-channel loop/channel:
A fibre-channel loop consists of drive expansion
enclosures that are connected to each other and to one or more RAID controllers.
A loop/drive channel can support multiple RAID controllers, multiple drive
expansion enclosures, and other addressable entities such as system-management
logic chips. Refer to your storage subsystem documentation for information
about controller-dependent hardware configuration. Some controllers might have
restrictions on the maximum number of disk drives that can be supported on a
loop, cabling restrictions, and other requirements.
v
SFP module ports:
The storage expansion enclosure supports large, complex,
and redundant disk drive loop configurations. Each ESM has two SFP module
ports. Each SFP module has an input and output port. A loop is created by
connecting one or more storage expansion enclosures to one or more RAID
controllers.
v
Fibre-channel cable restrictions:
RAID controllers use specific IBM fibre-channel
options. Refer to the
IBM System Storage Hardware Maintenance Manual, Problem
Determination Guide
, or your IBM representatives or resellers for the cable option
that is required for your configuration.
v
Power cabling:
The storage expansion enclosure uses two standard power
cables. You can connect the power cables to a primary power unit inside the
Figure 14. Storage expansion enclosure seven-segment enclosure ID
32
IBM System Storage DS3950 EXP395 Storage Expansion Enclosure: Installation, User’s, and Maintenance Guide
Summary of Contents for DS3950
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