Redundancy in enterprise storage networks using dual domain SAS configurations

Dual-domain SAS: servers in two-node cluster
This configuration, which is also known as a high availability (HA) cluster, at least one server must
have access to the storage network. The cluster interconnect provides redundancy in the event of host
bus adapter (HBA) or cable failure, as shown in Figure 4. Dual-domain SAS requires “active/active”
configurations. The “active/active” configurations permit both controllers to process I/Os, and either
controller can act as a standby. To use the dual-ports for redundant pathways, all drives must be SAS.
Figure 4. Multi-Path, 2-Node, HA cluster configuration
JBOD
JBOD
SAS drive
SAS drive
SAS drive
SAS drive
SAS drive
SAS drive
Server
Server
HBA
HBA
Server
Server
HBA
HBA
Cluster
Cluster
interconnect
interconnect
IO Module
IO Module
Expander
Expander
IO Module
IO Module
Expander
Expander
IO Module
IO Module
Expander
Expander
IO Module
IO Module
Expander
Expander
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