Connecting the controller enclosure and optional expansion enclosures
67
Cabling diagrams in this section show fault-tolerant cabling patterns. Controller and expansion modules are
identified by enclosure ID and IOM ID, such as 0A and 0B for controller enclosures, 1A and 1B for the first
expansion enclosure in a cascade, and so forth. When connecting multiple expansion enclosures, use reverse
cabling to ensure the highest level of fault tolerance, enabling controllers to access remaining expansion enclosures
if an expansion enclosure fails.
Cable requirements for expansion enclosures
When adding storage, use only Lenovo ThinkSystem or OEM-qualified cables, and observe the following
guidelines:
•
When installing SAS cables to expansion modules, use only supported HD mini-SAS x4 cables.
•
Qualified HD mini-SAS to HD mini-SAS 0.5 m (1.64') cables are used to connect cascaded enclosures in the
rack.
•
The maximum expansion cable length allowed in any configuration is 2 m (6.56').
•
When adding more than two drive enclosures, you may need to purchase additional cables, depending upon
number of enclosures and cabling method used.
•
You may need to order additional or longer cables when reverse-cabling a fault-tolerant configuration.
The rear panel view of the 2U12 and 2U24 controller enclosures are nearly identical to one another. The rear panel
views of the DS Series 2U expansion enclosures are also nearly identical to one another. The 5U84 uses the same
SBB IOM used in the 2U expansion enclosures, but the remaining CRUs accessible from the 5U rear panel differ
from those used in the 2U enclosures.
NOTE: For clarity, the schematic diagrams show only relevant details such as IOM face plate outlines and
expansion ports. For detailed illustrations see
“2U enclosure rear panel” (page 27)
.
