User`s manual

D-10
Appendix D SAS 826EL Backplane Specifications
The 826EL2 Backplane has two expanders which allow effective failover and
recovery.
D-9 Failover
Single Host Bus Adapter
In a single host bus configuration, the
backplane connects to one Host Bus
Adapter (HBA).
Single Host Bus Adapter
Failover
If the Expander or data path in Port A
fails, the system will automatically fail
over to Port B.
Dual Host Bus Adapter
In a Dual Host Bus Configuration, the
backplane connects to two Host Bus
Adapters (HBA).
Dual Host Bus Adapter Failover
If the Expander or data path in Port A
fails, the system will automatically fail
over to Port B. This maintains a full
connection to all drives.
SAS HBA
Port A
Expander 1
Port B
Expander 2
SAS HBA
Port A
Expander 1
Port B
Expander 2
SAS HBA
Port A
Expander 1
Port B
Expander 2
SAS HBA
SAS HBA
Port A
Expander 1
Port B
Expander 2
SAS HBA