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Install - Step 7 continued
Power up and cable optional DAEs
Setting the DAE enclosure addresses
You must set the enclosure address (EA) when power is on and the enclosure is not part of a
back-end bus; you cannot change the EA while the back end is connected.
Addressing overview
You add DAEs to a CX4 series storage system along Fibre Channel back-end buses
that start at I/O modules in the SPE. Each disk enclosure in a bus must have a unique
enclosure address (also called an EA, or enclosure ID) that identifies the enclosure
and determines disk module IDs.
Every DAE that is not preinstalled in a cabinet before shipment has a default
enclosure address of 0. DAEs directly connected
to the SPE
retain EA 0; subsequent
DAEs connected together in a back-end bus should have incremental EAs of 1, 2, 3
and so on.
The CX4-120 SPE supports a single redundant Fibre Channel back-end bus, called bus
0. The bus consists of two independent loops. One loop starts at SP A, and the other
loop starts from SP B. They are paired, and share access to the same disk drives. If a
problem occurs on one loop, the bus can remain active through the other loop.
The CX4-120 can support 120 disks, or a maximum of eight disk-array enclosures on
its back-end bus.
Addressing rules
For the system to boot and operate, the first DAE — connected to port 0, slot 0 on both
SPs — must have enclosure address (EA) 0. A DAE with boot disks and the CX4-120
operating system is always assigned enclosure address 0 prior to shipment.
Setting the addresses
Follow these steps to set enclosure addresses on your DAEs:
1. Verify that the first DAE, connected to the SPS and containing the storage-system
software disks, is set as enclosure address 0. The address is indicated by the LED
next to the enclosure # symbol, as shown below.