Redundancy in enterprise storage networks using dual domain SAS configurations

archival, reference, and redundant highly-available applications. They are intended for use in an

environment where the drive workload is 40 percent or less.

Single SAS domain

There are many single points of failure in a single domain. Failure can originate from any controller,

expander device, JBOD or cable, as shown in Figure 1.

NOTE:

JBOD is the acronym for “Just a Bunch of Disks.” It refers to a

group of hard disks, usually in an enclosure, that may or may not

be RAID configured.

Figure 1. Single domain SAS storage network

JBOD

Disk drive

Server

Controller

IO Module

Expander

NOTE:

All figures in this technical brief using the “4 “ notation indicate a

4-lane bundled path. There are 4 wires per lane, or 16 total wires

in a 4x cable.