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Configuration Rules
How to connect SAS interfaces across the system and expansion enclosures:
SAS expansion cables will be available with the expansion enclosures. Note
that if many expansion enclosures are connected, a longer SAS external
cable (e.g., a 120cm cable) may be necessary for connecting an expansion
enclosure from the opposite direction offering high redundancy.
Both expansion links connects expansion enclosures from the system to the
nearest one, and then to the farthest.
Each expander controller on the SAS expansion enclosure
controls a “
SAS
Domain
” that connects one of the alternative interfaces on all of the disk
drives in the enclosure. For example, one expander unit controls Domain A.
The SAS Domains can be identified by the expanders’ locations, i.e., upper
controller slot (Controller A / Slot A). On the system, each controller can be
considered as managing a separate SAS Domain. With the help of the port
selector mechanism on the MUX boards, the idea of SAS Domain applies
even when SATA drives are used.
