HP (Hewlett-Packard) QR516B User Manual
In HP 3PAR Storage arrays with more than two nodes, failover behavior occurs on node pairs;
that is, if node 0 goes down, ports on node 0 fail over to node 1, if node 2 goes down, ports on
node 2 fail over to node 3, and so on. Conversely, when node 1 goes down, ports on node 1 fail
over to node 0, and when node 3 goes down, ports on node 3 fail over to node 2. When the
downed node is up again, the failed-over ports automatically fail back to their original ports.
During the failover and failback process, a short pause in I/O could be experienced by the host.
that is, if node 0 goes down, ports on node 0 fail over to node 1, if node 2 goes down, ports on
node 2 fail over to node 3, and so on. Conversely, when node 1 goes down, ports on node 1 fail
over to node 0, and when node 3 goes down, ports on node 3 fail over to node 2. When the
downed node is up again, the failed-over ports automatically fail back to their original ports.
During the failover and failback process, a short pause in I/O could be experienced by the host.
Persistent Ports Setup and Connectivity Guidelines
For Persistent Ports to function properly, specific cabling setup and connectivity guidelines that
need to be followed can be found in the HP 3PAR Command Line Interface Administrator’s Manual,
“Using Persistent Ports for Nondisruptive Online Software Upgrades.” See this document for other
information about Persistent Ports as well.
need to be followed can be found in the HP 3PAR Command Line Interface Administrator’s Manual,
“Using Persistent Ports for Nondisruptive Online Software Upgrades.” See this document for other
information about Persistent Ports as well.
The fabric switch ports connecting to the HP 3PAR array ports must support NPIV and have the
feature enabled in order for Persistent Ports to work.
feature enabled in order for Persistent Ports to work.
The showport command output includes Partner and FailoverState columns that display
the partner port <node>:<slot>:<port> information and failover state information, respectively.
FailoverState
the partner port <node>:<slot>:<port> information and failover state information, respectively.
FailoverState
values represent the failover state of the two ports listed in the N:S:P and
Partner
columns. The FailoverState value can be one of the following:
•
none
: No failover in operation
•
failover_pending
: In the process of failing over to partner
•
failed_over
: Failed over to partner
•
active
: The partner port is failed over to this port
•
active_down
: The partner port is failed over to this port, but this port is down
•
failback_pending
: In the process of failing back from partner
Use the showport HP 3PAR CLI commands to get the state of the persistent ports. In the output of
the showport command shown below, under the Partner column, port 1:1:1 is the partner port
that 0:1:1 would fail over to and 0:1:1 is the partner port to which 1:1:1 would fail over. When
Persistent Ports is not active, the FailoverState for the ports would indicate none.
the showport command shown below, under the Partner column, port 1:1:1 is the partner port
that 0:1:1 would fail over to and 0:1:1 is the partner port to which 1:1:1 would fail over. When
Persistent Ports is not active, the FailoverState for the ports would indicate none.
# showport
N:S:P Mode State ----Node_WWN---- - Port_WWN/HW_Addr- Type Protocol Label
Partner Failover State
0:0:1 initiator ready 50002ACFF70185E1 50002ACFF70185E1 disk SAS -
- -
0:1:1 target ready 2FF70002AC0185E1 2FF70002AC0185E1 host FC -
1:1:1 none
When a node is down during an online upgrade or node reboot, from the output of the showport
command, the FailoverState column would show that Persistent Ports is active. In the example
below, node 1 has gone down, Persistent Ports for 1:1:1 has become active on port 0:1:1, and
all filesystem I/O for port 1:1:1 is physically served by port 0:1:1.
command, the FailoverState column would show that Persistent Ports is active. In the example
below, node 1 has gone down, Persistent Ports for 1:1:1 has become active on port 0:1:1, and
all filesystem I/O for port 1:1:1 is physically served by port 0:1:1.
# showport
N:S:P Mode State ----Node_WWN---- - Port_WWN/HW_Addr- Type Protocol Label
Partner Failover State
0:0:1 initiator ready 50002ACFF70185E1 50002ACFF70185E1 disk SAS -
- -
0:1:1 target ready 2FF70002AC0185E1 2FF70002AC0185E1 host FC -
1:1:1 active
16
Configuring the HP 3PAR StoreServ Storage for Fibre Channel