Lenovo DM120S, Installation And Cabling Manual, Page: 40 / 70

In this document, slots and the slot ports are depicted as follows:
Shelf-to-shelf connection rules
When you have more than one disk shelf in a stack of disk shelves, they connect to each other through each
SAS domain (IOM A and IOM B) using the applicable “standard” or “double-wide” shelf-to-shelf cabling.
Your use of “standard” or “double-wide” shelf-to-shelf cabling depends on the configuration you have.
Standard shelf-to-shelf connectivity
• Standard shelf-to-shelf connectivity is used in multipath HA, multipath, single-path HA, and single-path
configurations.
• Standard shelf-to-shelf connectivity is what is being used in existing SAS storage configurations with
IOM3 and IOM6 modules: one cable connection is needed between isk shelves in each domain—domain
A (IOM A) and domain B (IOM B).
• Best practice is to use IOM ports 3 and 1 for standard shelf-to-shelf connectivity. From the logical first
shelf to the logical last shelf in a stack, you connect IOM port 3 to the next shelf's IOM port 1 in domain A
and then domain B.
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Installation and Cabling Guide for DM120S, DM240S, and DM600S