D-12
SC846 Chassis Manual
Single Host Bus Adapter
In a single host bus configuration, the
backplane connects to one Host Bus
Adapter (HBA).
PRI_J0
PRI_J1
PRI_J2
SEC_J0
SEC_J1
SEC_J2
J17
WWN
SAS HBA
Port A
Expander 1
Port B
Expander 2
Figure 3-3: Single HBA
The SAS-846EL2 backplane has two expanders which allow effective failover and
recovery.
D-9 Failover
PRI_J0
PRI_J1
PRI_J2
SEC_J0
SEC_J1
SEC_J2
J17
WWN
SAS HBA
Port A
Expander 1
Port B
Expander 2
Single Host Bus Adapter
Failover
If the Expander or data path in Port A
fails, the system automatically switches
to Port B.
Figure 3-4: Single HBA Failover
PRI_J0
PRI_J1
PRI_J2
SEC_J0
SEC_J1
SEC_J2
J17
WWN
SAS HBA
Port A
Expander 1
Port B
Expander 2
SAS HBA
Dual Host Bus Adapter
In a Dual Host Bus Configuration, the
backplane connects to two Host Bus
Adapters (HBA).
Figure 3-5: Dual HBA
PRI_J0
PRI_J1
PRI_J2
SEC_J0
SEC_J1
SEC_J2
J17
WWN
SAS HBA
Port A
Expander 1
Port B
Expander 2
SAS HBA
Dual Host Bus Adapter
Failover
If the Expander or data path in Port A
fails, the system automatically switches
to Port B. This maintains a full connec-
tion to all drives.
Figure 3-6: Dual HBA Failover