Fujitsu ETERNUS AX Series Installation And Cabling Manual page 25

| Controller-to-stack cabling worksheets and cabling examples for common multipath HA configurations |
Multipath HA with four onboard SAS ports, a quad-port SAS HBA, and two multi-shelf stacks
Four port pairs are available for this configuration: 0a/1b, 1a/0d, 0c/1d, and 1c/0b. You can cable port pairs in
the order in which they are identified (listed in the worksheet) or you can cable every other port pair (skip port
pairs).
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.
The following worksheet and cabling example shows port pairs being used in the order in which they are
listed in the worksheet: 0a/1b, 1a/0d, 0c/1d, and 1c/0b.
The following worksheet and cabling example shows port pairs being skipped to use every other one in the
list: 0a/1b and 0c/1d.
Note: If a third stack is added later, you use the port pair that was skipped.
25