Cisco Nexus 5000 Series Switch Fabric Manager Software Configuration Guide, NX-OS 4.0 (OL-16598-01, June 2008)

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17-3
Nexus 5000 Series Switch Fabric Manager Software Configuration Guide
OL-16598-01
Chapter 17 Distributing Device Alias Services
Device Alias Databases
Device Alias Databases
The device alias feature uses two databases to accept and implement device alias configurations.
• Effective database—The database currently used by the fabric.
• Pending database—Your subsequent device alias configuration changes are stored in the pending
database.
If you modify the device alias configuration, you need to commit or discard the changes as the fabric
remains locked during this period.
This section includes the following topics:
• Device Alias Modes, page 17-3
• Changing Device Alias Mode Guidelines, page 17-3
• Configuring Device Alias Modes, page 17-4
• About Device Alias Distribution, page 17-5
• Distributing the Device Alias Database, page 17-5
• About Creating a Device Alias, page 17-5
• Creating a Device Alias, page 17-6
• Committing Changes, page 17-6
• Discarding Changes, page 17-7
Device Alias Modes
You can specify that aliases operate in basic or enhanced modes.
When operating in basic mode, which is the default mode, the device alias is immediately expanded to
a pWWN. In basic mode, when device aliases are changed to point to a new HBA, for example, that
change is not reflected in the zone server. Users must remove the previous HBA’s pWWN, add the new
HBA’s pWWN, and then reactivate the zoneset.
When operating in enhanced mode, applications accept a device alias name in its “native” format.
Instead of expanding the device alias to a pWWN, the device alias name is stored in the configuration
and distributed in its native device alias format. So applications such as zone server, PSM or DPVM can
automatically keep track of the device alias membership changes and enforce them accordingly. The
primary benefit of operating in enhanced mode is that you have a single point of change.
Whenever you change device alias modes, the change is distributed to other switches in the network only
if device alias distribution is enabled or on. Otherwise, the mode change only takes place on the local
switch.
Note Enhanced mode, or native device alias-based configurations are not accepted in interop mode VSANs.
IVR zoneset activation will fail in interop mode VSANs if the corresponding zones have native device
alias-based members.
Changing Device Alias Mode Guidelines
When changing device alias modes, follow these guidelines: