Cold Failover Policy; Port Grouping Policy - Brocade Communications Systems A7533A - Brocade 4Gb SAN Switch Base Administrator's Manual

Cold Failover policy

All F_Ports for an N_Port that goes offline are failed over to other N_Ports. However, if the N_Port
fails to come online after the switch comes online, it triggers cold failover of its F_Ports. If any of
these F_Ports have a Preferred Secondary N_Port set, and if the Preferred Secondary N_Port is
online, those F_Ports fail over to the Preferred Secondary N_Port during cold failover. If the
Preferred Secondary N_Port is not online, those F_Ports are disabled. If the Preferred Secondary
N_Port is not set for any of these F_Ports, these F_Ports failover to any N_Ports on the switch so
that the F_Ports are evenly balanced across all the N_Ports belonging to the same N_Port group.
NOTE
Access Gateway incorporates a number of Failover and Failback policies to ensure maximum up time
for the servers.

Port Grouping policy

When connecting a switch in AG mode to multiple fabrics or isolating a subset of servers from other
servers, you can group a number of servers and its corresponding fabric ports. You can do this by
enabling the Port Grouping policy (PG), which can only be performed on N_Ports. Port groups
cannot be overlapped. This means that an N_Port cannot belong to two different groups.
The Failover and Failback policies remain the same within each port group and the Preferred
Secondary N_Port can only specify the N_Ports from the same port group. This is why it is
recommended to form groups before defining the preferred secondary path. This behavior is only in
Fabric OS v6.0.0. When upgrading from Fabric OS v6.0.0 to Fabric OS v6.1.0, the PG policy that
was enforced in Fabric OS v6.0.0 continues to be enforced in Fabric OS v6.1.0 and the port groups
are retained.
For example,
F_Ports 1 and 2 are using N_Port1 and N_Port1 goes offline, then F_Ports1 and 2 are routed
through N_Port2 because N_Port2 is in the same port group, pg0.
Figure 6
routed through that port will fail over to any of the N_Ports that are part of that port group and are
currently active. For example, if N_Port4 goes offline then F_Ports7 and 8 are routed through to
N_Port 3 as long as N_Port 3 is online because both N_Ports3 and 4 belong to the same port
group, PG2. If no active N_Ports are available, the F_Ports are disabled. The F_Ports belonging to a
port group do not failover to N_Ports belonging to another port group.
Access Gateway Administrator's Guide
53-1000605-02
Figure 8 on page 19 shows an example of pg0. If N_Port1 and 2 are in pg0 and
shows that if you create port groups and when an N_Port goes offline, the F_Ports being
Access Gateway policies
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