Dell POWEREDGE M1000E - Manual (Page 61)

Access Gateway Administrator’s Guide 41
53-1002743-01
Port Grouping policy
3
Port Grouping policy
Use the Port Grouping (PG) policy to partition the fabric, host, or target ports within an AG-enabled
module into independently operated groups. Use the PG policy in the following situations:
• When connecting the AG module to multiple physical or virtual fabrics.
• When you want to isolate specific hosts to specific fabric ports for performance, security, or
other reasons.
How port groups work
Create port groups using the ag --pgcreate command. This command groups N_Ports together as
“port groups.” By default, any F_Ports mapped to the N_Ports belonging to a port group will
become members of that port group. Port grouping fundamentally restricts failover of F_Ports to
the N_Ports that belong to that group. For this reason, an N_Port cannot be member of two port
groups. The default PG0 group contains all N_Ports that do not belong to any other port groups.
Figure 9 shows that if you have created port groups and then an N_Port goes offline, the F_Ports
being routed through that port will fail over to any of the N_Ports that are part of that port group
and are currently online. For example, if N_Port 4 goes offline, then F_Ports 7 and 8 are routed
through to N_Port 3 as long as N_Port 3 is online because both N_Ports 3 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 fail over to N_Ports belonging to another port group.
FIGURE 9 Port grouping behavior
When a dual redundant fabric configuration is used, F_Ports connected to a switch in AG mode can
access the same target devices from both of the fabrics. In this case, you must group the N_Ports
connected to the redundant fabric into a single port group. It is recommended to have paths fail
over to the redundant fabric when the primary fabric goes down. Refer to
Figure 10 .
F_Port1
F_Port2
F_Port3
N_Port2
N_Port1
N_Port4
N_Port3
F_Port4
PG1
PG2
F_Port5
AG
Fabric-1
Fabric-2
Storage
Array-1
Storage
Array-2
F_Port6
F_Port7
F_Port8