Cable Requirements For Expansion Enclosures; Sas Topology - Seagate Exos E 4U106 Hardware Installation And Maintenance Manual

After all cables (including PSU cables) are routed through the first two CMA baskets, route them around a

180º bend into the remaining four CMA baskets.
Figure 55 Enclosure Cables routed through CMA

Cable requirements for expansion enclosures

When adding storage, use only Seagate or OEM-qualified cables, and observe the following guidelines:
• When installing SAS cables to expansion modules, use only supported HD mini-SAS (SFF-8644) x4 cables.
• Qualified HD mini-SAS cables, not to exceed 5 m (16.40'), are used to connect cascaded enclosures in the rack.
• The maximum expansion cable length allowed in any configuration is 5 m (16.40').
• The minimum cable length through the CMA is 3 m (9.83')
• When adding more than two expansion enclosures, you may need to purchase additional cables, depending
upon number of enclosures and cabling method used.
• You may need to order additional or longer cables when cabling a fault-tolerant configuration.

SAS topology

It is possible to support different topologies of SAS with the 4U106 enclosure. There are two basic forms of
expansion topology as shown in
a chain (left illustration). The other topology is a star configuration (right illustration) that has each expansion
enclosure connected from the host (server attached JBOD configuration) or controller enclosure (EBOD
configuration).
A third example provided in
Figure 56 (page 62). One is a simple daisy chain of enclosures one after another in
Figure 57 (page 63), shows use of all SAS ports via the daisy chain cabling method.
Cable requirements for expansion enclosures 61