Route 5U Enclosure Host Cables And Expansion Data Cables - Seagate Exos E 2U12 Series Hardware Installation And Maintenance Manual

Route 5U enclosure host cables and expansion data cables

Fault tolerance and performance are key factors in determining how to best optimize your system and cabling configuration.
This topic assumes a fault-tolerant reverse cabling method, since it provides a method of maintaining access to all enclosures
in the chain, even if one of the enclosures fails or requires removal. If you use a straight-through cabling method, optimized for
high performance, it is less fault tolerant. When using straight-through cabling, a failed enclosure in the chain prevents access
to enclosures further down the chain until you address the fault.
You must comply with all SAS cabling requirements and confirm that they meet all related standards.
CAUTION Do not create invalid closed loops anywhere along the SAS port cabling configuration. A valid cabling
configuration is directional and does not contain any loops between components already in that cabling configuration. An
invalid closed loop introduces a circular flow into the cabling configuration that can degrade performance or cause failure.
To route 5U enclosure and expansion data cables:
1. Take the following actions to connect the host switch or HBA 0A to its related expansion modules. The example below has
3 expansion enclosures directly below the host switch or HBA.
IMPORTANT Best practice is to use the expansion Port A for input and Port C for output.
a. Connect an approved mini-SAS data cables to the host bus adaptor (HBA) or switch, 0A.
b. Connect the other end to into SAS port A of the first expansion enclosure, IOM 1A.
c. Insert a mini-SAS data cable from SAS port C in the first expansion enclosure, 1A, and connect the other end to SAS
port A in the second expansion enclosure, 2A.
d. Insert a mini-SAS data cable from SAS port C in the second expansion enclosure, 2A, and connect the other end to SAS
port A in the third expansion enclosure, 3A.
2. Take the following actions to connect the host switch or HBA 0B to its related expansion modules. The example below has
3 expansion enclosures directly below the host switch or HBA.
IMPORTANT Best practice is to use the expansion Port A for input and Port C for output.
a. Connect an approved mini-SAS data cables to the host bus adaptor (HBA) or switch, 0B.
b. Connect the other end to into SAS port A of the last expansion enclosure, IOM 3B.
c. Insert a mini-SAS data cable from SAS port C in the last expansion enclosure, 3B, and connect the other end to SAS port
A in the second expansion enclosure, 2B.
d. Insert a mini-SAS data cable from SAS port C in the second expansion enclosure, 2B, and connect the other end to SAS
port A in the third expansion enclosure, 1B.
Chapter 5 Installation of 5U enclosures
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