HP 3PAR Persistent Ports technology enables each host port on an HP 3PAR StoreServ node to carry a “Native” and a “Guest” identity(WWN information) almost all the time. The host ports on the Nodes will carry Guest WWN of the corresponding port on the partner node in a node pair. 3PAR Persistent Ports technology effectively configures the host path to redirect I/O requests from the “Native” port on one node to the “Guest” port on partner node in case of firmware upgrades, node failure or loss_sync events.The port failover is really transparent and most of the time the connected hosts will not trigger a nofication about the port failover from host side.
There is no Persistent Ports support on HP 3PAR OS 3.1.2 releases. Persistent Ports functionality is supported for HP 3PAR OS 3.1.2 and later only. Starting with HP 3PAR OS 3.1.3 support for FCoE connected hosts and iSCSI connected hosts has been added. .
For HP 3PAR StoreServ FC host ports, the following requirements must be met:
• The same host port on host facing HBAs in the nodes in a node pair must be connected to the same FC fabric and
preferably different FC switches on the fabric (for example, 0:1:1 and 1:1:1).
• The host facing HBAs must be set to “target” mode.
• The host facing HBAs must be configured for point-to-point connection (no support for “loop”).
• The FC fabric being used must support NPIV and have NPIV enabled.
When a Persistent Port failover occurs the Failover State of the host ports can be one of the following states:
• none—Failover not in operation.
• failover_pending—Failover to partner request has been issued but not yet completed (transient state).
• failed_over—This port is failed over to its partner.
• failback_pending—Failback request has been issued but not yet completed (transient state).
• active—The partner port is failed over to this port.
• active_down—The partner port failed over to this port, but this port is down, e.g., cable missing.
• active_failed—The partner port failed over to this port, but the action failed, e.g., FC switch did not have NPIV enabled.
On most occasions we will have to failback the port to restore the port state. Let's see the practical side of this,
with this command.
SYNTAX
From the output it is visible that the port is running on its normal state with failover status as none.
There is no Persistent Ports support on HP 3PAR OS 3.1.2 releases. Persistent Ports functionality is supported for HP 3PAR OS 3.1.2 and later only. Starting with HP 3PAR OS 3.1.3 support for FCoE connected hosts and iSCSI connected hosts has been added. .
For HP 3PAR StoreServ FC host ports, the following requirements must be met:
• The same host port on host facing HBAs in the nodes in a node pair must be connected to the same FC fabric and
preferably different FC switches on the fabric (for example, 0:1:1 and 1:1:1).
• The host facing HBAs must be set to “target” mode.
• The host facing HBAs must be configured for point-to-point connection (no support for “loop”).
• The FC fabric being used must support NPIV and have NPIV enabled.
When a Persistent Port failover occurs the Failover State of the host ports can be one of the following states:
• none—Failover not in operation.
• failover_pending—Failover to partner request has been issued but not yet completed (transient state).
• failed_over—This port is failed over to its partner.
• failback_pending—Failback request has been issued but not yet completed (transient state).
• active—The partner port is failed over to this port.
• active_down—The partner port failed over to this port, but this port is down, e.g., cable missing.
• active_failed—The partner port failed over to this port, but the action failed, e.g., FC switch did not have NPIV enabled.
On most occasions we will have to failback the port to restore the port state. Let's see the practical side of this,
3parLab cli% showportIn the above example, we can see that most of the ports are in "failed_over" state and some are "active_failed" state. We should use "controlport" command along with the "failback" option. Failback option Reverts a port failover status to the default. if port failover is currently active. The failed-over port should be specified
N:S:P Mode State ----Node_WWN---- -Port_WWN/HW_Addr- Type Protocol Label Partner FailoverState
2:2:3 target ready 2AE80002AD009247 22230002AD009247 free FC - 3:2:3 failed_over
2:2:4 target ready 2AE80002AD009247 22240002AD009247 free FC - 3:2:4 failed_over
3:2:3 target ready 2AE80002AD009247 23230002AD009247 free FC - 2:2:3 active_failed
3:2:4 target loss_sync 2AE80002AD009247 23240002AD009247 free FC - 2:2:4 active_failed
4:2:3 target ready 2AE80002AD009247 24230002AD009247 free FC - 5:2:3 failed_over
4:2:4 target ready 2AE80002AD009247 24240002AD009247 free FC - 5:2:4 failed_over
5:2:3 target ready 2AE80002AD009247 25230002AD009247 free FC - 4:2:3 active
5:2:4 target ready 2AE80002AD009247 25240002AD009247 free FC - 4:2:4 active
5:5:1 target ready 2AE80002AD009247 25510002AD009247 free FC - 4:5:1 none
5:5:2 target ready 2AE80002AD009247 25520002AD009247 free FC - 4:5:2 none
6:2:1 target ready 2AE80002AD009247 26210002AD009247 free FC - 7:2:1 failed_over
6:2:2 target ready 2AE80002AD009247 26220002AD009247 free FC - 7:2:2 failed_over
6:2:3 target ready 2AE80002AD009247 26230002AD009247 free FC - 7:2:3 failed_over
6:2:4 target ready 2AE80002AD009247 26240002AD009247 free FC - 7:2:4 failed_over
6:5:1 target ready 2AE80002AD009247 26510002AD009247 free FC - 7:5:1 failed_over
6:5:2 target ready 2AE80002AD009247 26520002AD009247 free FC - 7:5:2 failed_over
7:2:1 target ready 2AE80002AD009247 27210002AD009247 free FC - 6:2:1 active
7:2:2 target ready 2AE80002AD009247 27220002AD009247 free FC - 6:2:2 active
7:2:3 target ready 2AE80002AD009247 27230002AD009247 free FC - 6:2:3 active
7:2:4 target ready 2AE80002AD009247 27240002AD009247 free FC - 6:2:4 active
7:5:1 target ready 2AE80002AD009247 27510002AD009247 free FC - 6:5:1 active
7:5:2 target ready 2AE80002AD009247 27520002AD009247 free FC - 6:5:2 active
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with this command.
SYNTAX
controlport failback node:slot:port
3parLab cli%the host port 3:2:4 is failed_over to to it's partner port 2:2:4 and we should failback the partner port(2:2:4) to restore the state.
3parLab cli% showport 3:2:4
N:S:P Mode State ----Node_WWN---- -Port_WWN/HW_Addr- Type Protocol Label Partner FailoverState
3:2:4 target loss_sync 2AE80002AD009247 23240002AD009247 free FC - 2:2:4 active_failed
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1
3parLab cli% controlport failback 2:2:4
Are you sure you want to run controlport failback on port 2:2:4?
select q=quit y=yes n=no: y
3parLab cli% showport 3:2:4
N:S:P Mode State ----Node_WWN---- -Port_WWN/HW_Addr- Type Protocol Label Partner FailoverState
3:2:4 target loss_sync 2AE80002AD009247 23240002AD009247 free FC - 2:2:4 none
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1
3parLab cli%
From the output it is visible that the port is running on its normal state with failover status as none.
this is incorrect, the failback above should be controlport failback 3:2:4
ReplyDelete(extracted from the HPE Guide)
failover
Fails the specified port over to a failover partner port using the virtual ports mechanism, if a valid
partner port is present.
failback
Reverts a port failover using the persistent ports mechanism, if port failover is currently active.
The failed-over port should be specified with this command.