C-12
SC933 Chassis Manual
The SAS-933EL2 backplane has two expanders which allow effective failover and
recovery.
C-10 Failover
Single Host Bus Adapter
In a single host bus configuration, the
backplane connects to one Host Bus
Adapter (HBA).
SEC_J2
SEC_J1
SEC_J0
PRI_J2
PRI_J1
B3
B2
B1
A3
A2
A1
PRI_J2
PRI_J1
PRI_J0
PRI_EEPROM
A3
A2
A1
SAS HBA
Port A
Expander 1
Port B
Expander 2
SAS HBA
Single Host Bus Adapter
Failover
If the expander or data path in Port
A fails, the system will automatically
switch over to Port B.
SEC_J2
SEC_J1
SEC_J0
PRI_J2
PRI_J1
B3
B2
B1
A3
A2
A1
PRI_J2
PRI_J1
PRI_J0
PRI_EEPROM
A3
A2
A1
Port A
Expander 1
Port B
Expander 2
Figure C-7: Failover with a Single HBA