• Lost connectivity to storage device naa.60a9800043346534645a433967325334. Path vmhba35:C1:T0:L7 is down. Affected datastores: "Storage1"
• Path redundancy to storage device or Lost path redundancy to storage device naa.60a9800043346534645a433967325334. Path vmhba35:C1:T0:L7 is down.

VMware VirtualCenter 2.5.x
VMware ESXi 4.1.x Embedded
VMware vSphere ESXi 5.0
VMware ESX Server 3.5.x
VMware vSphere ESXi 5.1
VMware ESXi 3.5.x Embedded
VMware ESXi 3.5.x Installable
VMware ESXi 4.0.x Embedded
VMware vCenter Server 5.0.x
VMware ESX 4.0.x
VMware vCenter Server 4.0.x
VMware ESXi 4.0.x Installable
VMware ESXi 4.1.x Installable
VMware ESX 4.1.x
VMware vCenter Server 5.1.x
VMware vCenter Server 4.1.x
VMware vSphere ESXi 5.5

The storage device reading (vmhba35:C1:T0:L7) mentioned in the example earlier contains several potential failure points:

• vmhba35 - HBA (Host Bus Adapter)
• C1 - Channel
• T0 - Target (Storage processor port)
• L7 - LUN (Logical Unit Number or Disk Unit)

Note: All mentioned commands are available via vSphere Command-LineorVMware vSphere Management Assistant.

1. Identify the available storage paths to the reported storage device by running the esxcfg-mpath -l command. For more information, see Obtaining LUN pathing information for ESX hosts (1003973).
2. Check that a rescan does not restore visibility to the targets. Follow the steps provided in Performing a rescan of the storage (1003988) to rescan the storage device by using the command-line interface and VMware vSphere Client.
3. Determine whether the connectivity issue is with the iSCSI storage or the fiber storage. Perform one of the following depending on what your connectivity issue is:
    
   • To troubleshoot the connectivity to the iSCSI storage using the software initiator:
      
     1. Check whether a ping to the storage array fails from ESX. For more information, see Testing network connectivity with the Ping command (1003486).
     2. Check whether a vmkping to each network portal of the storage array fails. For more information, see Testing VMkernel network connectivity with the vmkping command (1003728).
     3. Check that the initiator is registered on the array. Contact your storage vendor for instructions on this procedure.
     4. Check that the following physical hardware is correctly functioning:
         
        • Ethernet switch
        • Ethernet cables between the switch and the ESX host

        • Ethernet cables between the switch and the storage array

   • To troubleshoot the connectivity to the fiber attached storage, check the following:
     
      
     1. The fiber switch zoning configuration permits the ESX host to see the storage array. Consult your switch vendor if you require assistance.
     2. The fiber switch propagates RSCN messages to the ESX hosts. 
         
4. Check the physical hardware for the following:
    
   • The storage processors on the array.
   • The fiber switch and the Gigabit Interface Converter (GBIC) units in the switch.
   • The fiber cables between the fiber switch and the array.
   • The array itself.

Note: You must rescan after any change is made to verify whether the targets are detected.