Deployment KB: Dell EMC Unity: How to Troubleshoot Fiber Channel Port connectivity issue in Unity.

After installation of new Unity storage the Fiber Channel connectivity links start showing unstable, the ports are continually changing status with the same same status showing on both storage and switch sides.


                               
Resolution

• Since issue showing on multiple  FC ports, he port configuration may be an issue, check that the speed settings match at both switch and storage sides.
• Dell EMC Unity uses Multi-Mode SFP connectors by default, ensure that FC cables using for connectivity should be Multi-Mode cables.
  • Unity CNA ports supports Single mode SFP for Synchronous Replication requirement so ensure that SFP type and cable type are matching.
  • Single-Mode cables used for connectivity in Multi-Mode SFP connectors will show unstable connectivity.
• Follow below KB for more details on FC cables 
  • Dell EMC Unity supported Fiber Cables KB-543610

Other troubleshooting steps for identifying the connectivity issues are as follows:

• From the Unisphere GUI verify the ports showing issue on storage side.
• From Switch login check which all are ports showing issue on switch side.
• Verify the Port Speed settings are identical for all ports at Switch side and storage side ( Suggested to have Auto or else select the speed as per storage and Switch port speed).
• Clear the error status at switch port level and monitor the error status.
• Find the following command references for Brocade Switch.
  • To view the current stats and errors for a port, use the following command.

• To clear the stats on single port, use following command.

• To clear the stats for a range of ports, use the following command.

• To clear all the switch port and diagnostic in one go, use the following command.

                                                                 

Follow Below steps, verify the port error status. Clear the error status after each test and follow next step

1. Re-seat the cable on both ends. Before re-seating the cable, verify it is the correct one, the link/speed LED may not be illuminated.
2. Re-seat the SFP on the switch and array (if present).
3. Replace the cable with a known good cable.
4. Test with a known good SFP on the switch and array (if present).
5. Move the cable to different switch port. Note: If port comes online, depending if port zoning or WWN zoning was implemented, the zoning may need to be updated to establish the connection.
6. Log into the Fiber Channel switch and disable/enable switch port in which the array port is plugged into. Note: before disabling the FC port verify it shows down, if the port is listed as up, the port may not be the correct port.  

If the issue isn't resolved, and the port is still down, contact your service provider.