Fibre Channel Loop And Id Settings; Enclosure Id Settings; Setting The Interface Options - IBM TotalStorage DS4000 EXP700 Installation, User's, And Maintenance Manual

Figure 20. Setting the interface options

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 switch setting and
the physical location (bay) of the hard disk drive.

Enclosure ID settings

Each storage expansion enclosure in a DS4000 storage subsystem drive loop must
have a unique drive enclosure ID. DS4000 controllers use a combination of the
enclosure ID and the number of the physical slot that a fibre channel hard drive
occupies to create a unique fibre channel loop address or arbitrated loop physical
address (AL_PA) for each drive in a fibre channel drive loop. The enclosure ID
consists of two digits, a tens digit (x10) and ones digit (x1).
Attention:
DO NOT use the tens digit (x10) setting. Use only the ones digit (x1) setting to set
unique server IDs or enclosure IDs.
Give each storage expansion enclosure in a redundant drive loop a unique ones
digit (x1) ID. This setting will enforce hard AL_PAs (unchangeable between fibre
channel Loop Initializations [LIPs]) for the drives and facilitate drive loop problem
troubleshooting in the event of an error. If the ones digits are not unique, two or
more devices will have the same hard AL_PA. In such a case, the controller will use
soft AL_PAs for the devices that have identical hard AL_PAs.
The problem with soft addressing is that addresses may change between LIPs. This
possibility increases the difficulty of troubleshooting drive loop problems, since one
cannot easily ascertain whether the same device with a different address or
different device may be causing a problem.
Note: The storage expansion enclosure is shipped with 00 as the default server ID
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IBM TotalStorage DS4000 EXP700 and EXP710 Storage Expansion Enclosures: Installation, User's, and Maintenance Guide
1 Gb/s
X10
Tray Number
When connecting the storage expansion enclosure to a storage server,
setting. When you connect the storage expansion enclosure to a storage
server, you must set the storage expansion enclosure enclosure ID setting to
a value other than 00. Each server unit should have a unique ID if it is going
2 Gb/s
X1 Conflict
1 Gb/s 2 Gb/s
X10 X1
Conflict
Tray Number
Green 2 GB/s LED
Amber Conflict LED