Dell POWEREDGE M1000E - Manual (Page 85)

Fabric OS Command Reference 57
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aptPolicy
2
This policy optimizes the utilization of the available paths by allowing I/O traffic
between different source fabric device (SID) or destination fabric device (DID)
pairs to use different paths. As a result, every distinct flow in the fabric can take a
different path through the fabric. Effectively, device based routing works the same
as exchange-based routing but does not use the Originator Exchange ID (OXID)
field. This helps to ensure that the exchanges between a pair of devices stay in
order.
Device-based routing is also a form of Dynamic Path Selection (DPS). DPS
assigns communication paths between end devices in a fabric to egress ports in
ratios proportional to the potential bandwidth of the ISL, ICL, or trunk group. When
there are multiple paths to a destination, the input traffic is distributed across the
different paths in proportion to the bandwidth available on each of the paths. This
improves utilization of the available paths and reduces possible path congestion.
3
Exchange-based routing policy (default). With this policy, the path chosen for an
ingress frame is based on all of the following items:
•
The ingress port on which the frame was received.
•
The FC address of the SID for this frame.
•
The FC address of the DID for this frame.
•
The FC OXID for this frame.
This policy optimizes the utilization of the available paths by allowing I/O traffic
between different SID, DID, or OXID pairs to use different paths. All frames
received on an ingress port with the same SID, DID, or OXID parameters take the
same path unless there is a fabric event. Refer to dlsSet for the definition of a
fabric event.
This policy does not support static routes. DLS is always enabled and the DLS
setting cannot change with this policy.
-ap ap_policy
Specifies an additional AP policy option supported under both port-based and
exchange-based policies. If logical fabrics are enabled, this command is valid only
on the base switch. The following policies are supported:
0
AP Shared Link Policy (default).
1
AP Dedicated Link Policy. This policy dedicates some links to the ingress traffic
and some links to the egress traffic. This policy relieves internal congestion in an
environment where there is a large amount of traffic going through both directions
at the same time. In addition, it can reduce the impact of slow devices on the
overall switch performance.
EXAMPLES To display the current APT policy:
switch:admin> aptpolicy
Current Policy: 3 1(ap)
3 1 (ap): Default Policy
1: Port Based Routing Policy
2: Device Based Routing Policy (FICON support only)
3: Exchange Based Routing Policy
0: AP Shared Link Policy
1: AP Dedicated Link Policy