Device mapping considerations – Dell POWEREDGE M1000E User Manual
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Access Gateway Administrator’s Guide
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Access Gateway mapping
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1. Static device mapping to N_Port (if defined)
2. Device mapping to N_Port group (if defined)
For more information, refer to
3. Automatic Device Load Balancing within a port group (if enabled)
For more information, refer to
4. Port mapping to an N_Port
5. Port mapping to an N_Port in a port group (if defined)
For more information, refer to
Device mapping considerations
Consider the following points when using device mapping:
•
If the N_Port is disabled, all devices that are mapped to it will be disabled. Depending on the
effective failover policy, the devices will be enabled on other N_Ports.
•
Similar to port mappings, device mappings are affected by changes to underlying F_Ports. In
other words, if an F_Port needs to be taken offline, both the physical device and all virtual
nodes behind it will momentarily go offline.
•
Once devices are mapped to an N_Port rather than an N_Port group, they cannot be
automatically rebalanced to another N_Port if an additional N_Port comes online.
•
There can be cases where two NPIV devices logging in through the same F_Port are mapped to
two different N_Ports that are connected to two different fabrics. In this case, both NPIV
devices may be allocated the same PID by their respective fabrics. Once Access Gateway
detects this condition, it will disable that F_Port, and the event will be logged.
NOTE
Access Gateway algorithms reduce the chances of PID collisions, but they cannot be totally
eliminated. In some cases, you may be able to configure your virtual or physical fabrics to
further reduce PID collisions.
•
Device mapping is not supported when firmware is downgraded to Fabric OS v6.3.x or earlier.
You must delete device mappings before downgrading or disable Device Load Balancing.
•
Static and dynamic device mapping are only supported on the edge module in a cascaded
Access Gateway configuration.
•
When mapping devices to a port group, make sure that all ports in the group have the same
NPIV login limit. If some ports have a lower login limit than the other ports, and there are many
logins to the group, some devices will repeatedly attempt to connect to the device with the
lower limit (because it has the fewest logins) and fail to connect.