7065Cabling.fm
Draft Document for Review August 30, 2007 12:59 am
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IBM System Storage DS3000: Introduction and Implementation Guide
Figure 3-2 EXP3000 attachment - single controller and single ESM configuration
This is a fully functional configuration, but there is no redundancy on the drive side. If there is
an EXP3000 failure or a broken SAS cable, some EXP3000s could lose connection
unnecessarily.
Dual controller DS3000
We therefore recommend to use a dual controller DS3000 and two ESMs in each EXP3000.
Figure 3-3 shows the SAS cable connections in this scenario.
Use top-to-bottom order on the left-side controller and EXP3000 ESMs. The right-side
controller and EXP3000 ESMs should be connected in bottom-to-top order. This will eliminate
single point of failure on the drive side. If any EXP3000 fails completely, the remaining
EXP3000s will still be accessible through one or the other DS3000 controller.
