ESXi Host Missing Storage Targets Due to Cisco Fabric FCNS Desynchronization

Products

• VMware vSphere ESXi

Issue/Introduction

Fibre Channel (FC) Host Bus Adapters (HBA) on VMware ESXi hosts fail to discover target storage arrays or establish target logins despite valid zoning configured on the switch fabric.

• ESXi hosts lose visibility to a specific number of storage targets (e.g., only 6 of 8 paths visible).
• Issues occur following a host reboot or storage DRS activity.
• esxcli storage san fc reset completes successfully but does not restore the missing paths.
• Zoning is confirmed correct on the switch, but the HBA fails to discover all presented targets.

Environment

• VMware vSphere ESXi 8.x
• Cisco MDS Fibre Channel Fabric
• Cisco UCS Hardware

Cause

The Fibre Channel Name Server (FCNS) database has become desynchronized between on the fabric switchs. This prevents the ESXi host HBA from successfully completing fabric registration for all targets, even if zoning is correct.

Resolution

1. Perform a host-side fabric login reset to rule out transient initialization issues:
   • SSH to the ESXi host.
   • Run: esxcli storage san fc reset -A vmhbaX (Replace vmhbaX with the affected adapter).
2. If paths do not return, Reach out to the Fabric team/vendor to review fabric and determine  if the (FCNS) database has become desynchronized.  

Additional Information

• For host-side reset procedures, see KB 324547.
• To speak with a customer representative or a Support Engineer see Contact Support. Scroll to the bottom of the page and click on your respective region.