When connecting a high speed cisco UCS Fabric Interconnect (like the 6454) to Cisco MDS Fibre Channel switches, you might encounter error-disabled ports causing the port-channel to go down. Specifically for 8 Gbps speeds you need to enter 1 additional command per port that’s participating in the port-channel:

int fc1/17
switchport fill-pattern IDLE speed 8000

For each fc port on the MDS you need to enter this command, followed by a “shut / no shut” and the error disabled problems are most likely gone.

Check to see the port config:

show run int fc1/17

Or whatever port you configured to use the fill-pattern.

Source: Cisco