Each ThinkSystem DS Series Expansion Unit ships with two SAS I/O expansion modules. Each expansion
module provides 12 Gb SAS connectivity to the internal drives, and it has three external 12 Gb SAS x4
ports (Mini-SAS HD SFF-8644 connectors labelled Port A, Port B, and Port C) that are used for
connections to the ThinkSystem DS4200 and for daisy chaining the expansion enclosures between each
other.
The expansion port on the controller module is connected to the Port A on the expansion module, and the
Port C on the expansion module is connected to the Port A on the expansion module in the adjacent
enclosure, and so on.
Note: The Port B on the expansion module is not used.
The expansion enclosure connectivity topology is shown in the following figure.
Figure 7. Expansion unit connectivity topology
The following table lists ordering information for the supported expansion enclosure connectivity options.
Table 7. Expansion unit connectivity options
Description
Part
number
Feature
code
Quantity per one
expansion unit
External MiniSAS HD 8644/MiniSAS HD 8644 0.5M Cable
00YL847
AU16
2*
External MiniSAS HD 8644/MiniSAS HD 8644 1M Cable
00YL848
AU17
2*
External MiniSAS HD 8644/MiniSAS HD 8644 2M Cable
00YL849
AU18
2*
External MiniSAS HD 8644/MiniSAS HD 8644 3M Cable
00YL850
AU19
2*
* One cable per expansion module; two cables are required per each expansion enclosure.
Lenovo ThinkSystem DS4200 Storage Array
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