Port grouping policy considerations – Dell POWEREDGE M1000E User Manual

Page 59

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Access Gateway Administrator’s Guide

39

53-1001760-01

Port Grouping policy

3

Setting the current fabric name monitoring timeout value

1. Connect to the switch and log in using an account assigned to the admin role.

2. Enter the ag --pgfnmtov command, followed by a value.

switch:admin> ag --pgfnmtov 100

This sets the timeout value to 100 seconds.

NOTE

The pgfnmtov command is blocked on a Brocade 8000.

Port Grouping policy considerations

Following are the considerations for the Port Grouping policy:

A port cannot be a member of more than one port group.

The PG policy is enabled by default in Fabric OS 6.0 and higher. A default port group “0” (PG0)
is created, which contains all ports on the AG.

APC policy and PG policy are mutually exclusive. You cannot enable these policies at the same
time.

If an N_Port is added to a port group or deleted from a port group and login balancing is
enabled or disabled for the port group, the N_Port maintains its original failover or failback
setting. If an N_Port is deleted from a port group, it automatically gets added to port group 0.

When specifying a preferred secondary N_Port for a port group, the N_Port must be from the
same group. If you specify an N_Port as a preferred secondary N_Port and it already belongs to
another port group, the operation fails. Therefore, it is recommended to form groups before
defining the preferred secondary path.

If the PG policy is disabled while a switch in AG mode is online, all the defined port groups are
deleted, but the port mapping remains unchanged. Before disabling the PG policy, you should
save the configuration using the configupload command in case you might need this
configuration again.

If N_Ports connected to unrelated fabrics are grouped together, N_Port failover within a port
group can cause the F_Ports to connect to a different fabric and the F_Ports may lose
connectivity to the targets they were connected to before the failover, thus causing I/O
disruption as shown in

Figure 9

on page 34. Ensure that the port group mode is set to

Managed Fabric Name Monitoring (MFNM)

mode. This monitors the port group to detect

connection to multiple fabrics and disables failover of the N-ports in the port group. For more
information on MFNM, refer to

“Enabling Managed Fabric Name Monitoring mode”

on

page 38.

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