Lenovo DM120S, Installation And Cabling Manual, Page: 51 / 70

Chapter 9. How to read a worksheet to cable controller-to-
stack connections for multipathed connectivity
You can use this example to guide you through how to read and apply a completed worksheet to cable
controller-to-stack connections for disk shelves with IOM12 modules for multipathed connectivity.
Before you begin
Your HA pair configuration cannot be a DM3000x, DM5000x, or DM7000x configuration. DM3000x,
DM5000x, or DM7000x configurations use a unique worksheet; see the “Controller-to-stack cabling
worksheets and cabling examples for common DM3000x, DM5000x, or DM7000x configurations” section.
About this task
• This procedure references the following worksheet and cabling example to demonstrate how to read a
worksheet to cable controller-to-stack connections. The configuration used in this example is a multipath
HA configuration with two quad-port SAS HBAs (eight SAS ports) on each controller and two stacks of
disk shelves with IOM12 modules. Port pairs are cabled by skipping every other port pair in the worksheet.
Note: When you have more port pairs than you need to cable the stacks in your system, the best practice
is to skip port pairs to optimize the SAS ports on your system. By optimizing SAS ports, you optimize your
system's performance.
• If needed, you can refer to the “SAS cabling rules” section for information about the controller slot
numbering convention, shelf-to-shelf connectivity, and controller-to-shelf connectivity (including the use
of port pairs).
The port pairs are cabled using every other port pair in the worksheet: 1a/2b and 1c/2d. The port pairs being
skipped to use every other one in the list: 1a/2b and 1c/2d.
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