VMware vCenter does not trigger "Path Redundancy Restored" events for Cisco UCS servers after a storage path connectivity failure is resolved.

Products

• VMware vSphere ESXi

Issue/Introduction

Symptoms:

• While path redundancy loss is correctly reported, the subsequent restoration of connectivity does not generate the expected high-level vCenter notification, despite the paths returning to an "Active" state.
• vCenter logs esx.problem.storage.redundancy.lost when paths go down.
• vCenter fails to log esx.clear.storage.redundancy.restored when connectivity returns.
  
  

Environment

VMware vSphere ESX 8.0.u3

Cause

The root cause is the specific design and behavior of the Cisco nfnic driver. Unlike other drivers that restore a previously "dead" path, the nfnic driver performs a path cleanup and replacement:

• Path Cleanup: When a path fails, the driver removes the dead path from the stack (vob.scsi.scsipath.remove).
• Path Re-addition: Upon recovery, the driver adds a new path with a different target ID instead of restoring the existing one.
• State Transition Mismatch: Because the driver bypasses the standard "dead-to-active" transition for the original path, the Native Multipathing Plugin (NMP) in the vmkernel cannot correlate the new path addition with the prior redundancy loss.
• Consequently, the high-level "restored" event is not triggered.

Resolution

To monitor and confirm storage path restoration on Cisco UCS hosts, implement one of the following monitoring strategies:

 

Option 1:VMware Aria Operations for Logs (Recommended)

Configure ESXi Syslog to forward to Aria Operations for Logs. Create custom alerts by monitoring the vobd.log for specific restoration strings that indicate connectivity is back:

vob.scsi.scsipath.add
vob.scsi.scsipath.pathstate.on

 

Option 2: SNMP Traps or Remote Syslog

Configure the ESXi host to forward raw syslog data or send SNMP traps to a third-party monitoring tool capable of alerting on the vob.scsi path addition events.

 

Option 3: Manual VOB(VMkernel Observation) to vCenter Event Mapping (Advanced)

Manually modify the ESXi configuration files to promote specific VOB messages (such as vob.scsi.scsipath.add) to vCenter events.

Note: This is generally not recommended for large environments as it can significantly increase vCenter database size and cause event flooding.