HP LeftHand P4000 Virtual SAN Appliance Software - Manual (Page 58)

Physical and logical interfaces
The two NICs in the storage system are labeled as listed in Table 18 (page 58) . If both interfaces
are bonded for failover, the logical interface is labeled bond0 and acts as the master interface.
As the master interface, bond0 controls and monitors the two slave interfaces which are the physical
interfaces.
Table 18 Bonded network interfaces
Failover description Failover name
Logical interface acting as master bond0
Physical interface acting as slave eth0 or Motherboard:Port1
Physical interface acting as slave eth1 or Motherboard:Port2
The logical master interface monitors each physical slave interface to determine if its link to the
device to which it is connected, such as a router, switch, or repeater, is up. As long as the interface
link remains up, the interface status is preserved.
Table 19 NIC status in Active-Passive configuration
The NIC is If the NIC status is
Currently enabled and in use Active
Slave to a bond and available for failover Passive (Ready)
Slave to a bond and no longer has a link Passive (Failed)
If the active NIC fails, or if its link is broken due to a cable failure or a failure in a local device to
which the NIC cable is connected, then the status of the NIC becomes Passive (Failed) and the
other NIC in the bond, if it has a status of Passive (Ready), becomes active.
This configuration remains until the failed preferred interface is brought back online. When the
failed interface is brought back online, it becomes Active. The other NIC returns to the Passive
(Ready) state.
Requirements for Active-Passive
To configure Active-Passive:
•
Both NICs should be enabled.
•
NICs should be connected to separate switches.
Which physical interface is preferred
When the Active-Passive bond is created, if both NICs are plugged in, the SAN/iQ software
interface becomes the active interface. The other interface is Passive (Ready).
For example, if Eth0 is the preferred interface, it will be active and Eth1 will be Passive (Ready).
Then, if Eth0 fails, Eth1 changes from Passive (Ready) to active. Eth0 changes to Passive (Failed).
Once the link is fixed and Eth0 is operational, there is a 30–second delay and then Eth0 becomes
the active interface. Eth1 returns to the Passive (Ready) state.
NOTE: When the active interface comes back up, there is a 30–second delay before it becomes
active.
58 Managing the network