Resolving Device Alias Merge Failures; Device Alias Best Practices - Cisco MDS 9000 Series Configuration Manual

Resolving Device Alias Merge Failures

Resolving Device Alias Merge Failures
The most common device-alias merge failure issues occur when merging databases. When a device-alias
merge fails, we recommend that you review the syslog messages on the switch in which the merge was initiated
in order to identify the issues. The application server in each fabric that is responsible for the merge is indicated
by the term Merge Master in the messages.
In this example, the syslog messages indicate that the merge failed as a result of a database mismatch:
2007 Apr
switch wwn 20:00:00:0d:ec:2f:c1:40,ip 172.20.150.38, remote switch wwn
20:00:00:0d:ec:04:99:40, ip 172.20.150.30
2007 Apr
due to mismatch.
Note
Use the device-alias distribute command to initiate a merge or remerge of device-alias databases. Use the
device-alias commit command to push a switch's device-alias database to all the other switches in a fabric.
If the switches whose device-alias databases are not merged (more than one merge master is shown in the
output of the show cfs merge status name device-alias command), then the device-alias commit command
causes the device-alias databases that are not merged to be overwritten.

Device Alias Best Practices

This section lists the best practices that you should follow when creating and using device aliases:
• Device aliases should be used to simplify the management of world wide names (WWNs) whenever
• Device-alias names are case-sensitive.
• Operate device aliases in Enhanced mode whenever possible. In Enhanced mode, applications accept a
• Preplan device-alias configurations and implement a consistent naming convention.
• Keep documented backups of all device-alias configurations.
• Plan for what the final device-alias database should be after the merge, before attempting to resolve
Cisco MDS 9000 Series Fabric Configuration Guide, Release 8.x
172
9 15:52:42 switch-1 %CFS-3-MERGE_FAILED: Merge failed for app device-alias, local
9 15:52:42 switch-1 %DEVICE-ALIAS-3-MERGE_FAILED: Databases could not be merged
possible. It is easier to identify devices with aliases rather than with WWNs. Hence, you should assign
aliases to WWNs to easily identify the WWNs.
device-alias name in its native format, rather than expanding the alias to a port world wide name (pWWN).
Because applications such as zone server, Inter-VSAN Routing (IVR), Port Security Manager (PSM),
and Dynamic Port VSAN Membership automatically track and enforce device-alias membership changes,
you have a single point of change.
Note
Interop mode VSANs do not accept Enhanced mode configurations.
merge failures. This can prevent traffic disruptions caused by accidentally overwriting device-alias entries.
Distributing Device Alias Services