User`s manual

C-12
SC836 Chassis Manual
The SAS-836EL2 backplane has two expanders which allow effective failover and
recovery.
C-9 Failover
Single Host Bus Adapter
In a single host bus conguration, 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 C-8: Single 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
Single Host Bus Adapter
Failover
If the Expander or data path in Port A
fails, the system automatically switches
to Port B.
Figure C-9: 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 Conguration, the
backplane connects to two Host Bus
Adapters (HBA).
Figure C-10: 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 C-11: Dual HBA Failover