NFS mount fails with the error “The name <NFS_datastore> already exists”

Products

• VMware vSphere ESX 7.x
• VMware vSphere ESX 8.x

Issue/Introduction

• After an All Paths Down (APD) event, the NFS datastore is shown as Not Accessible and Not Mounted.
  
  #esxcli storage nfs list
  Volume Name               Host(s)                   Share                             Vmknics  Accessible  Mounted  Connections  Read-Only  Security       isPE   Hardware Acceleration
  ------------                  ------------------------  -------------------------                -------        ----------        -------       -----------        ---------         --------           -----  ---------------------
  (NFS_datastore>        <Hostname>        /#####/#########                 None         false           false              1               false          AUTH_SYS  false  Unknown
  
  
• Attempts to remount the NFS volume fail with the error: "The name <NFS_datastore> already exists"
  
  
• Attempts to restore the NFS mount → No change observed
  esxcfg-nas -r
  
  

Environment

VMware vSphere ESXi 7.x
VMware vSphere ESXi 8.x

Cause

• The NFS datatsore/device entered an All Paths Down (APD) state.
  
  
• In the /var/run/log/vmkernel.log file, similar entries are seen: 
  YYYY-MM-DDTHH:MM:SS In(14) vobd[2097955]:  [vmfsCorrelator] 8803287877464us: [vob.vmfs.nfs.server.disconnect] Lost connection to the server ############## mount point ###########, mounted as ########-########-####-############  ("/#####/#########")
  YYYY-MM-DDTHH:MM:SS In(14) vobd[2097955]:  [APDCorrelator] 8803379217545us: [esx.problem.storage.apd.start] Device or filesystem with identifier [########-########-####-############] has entered the All Paths Down state.

Resolution

• Resolve the APD condition for datastore at the storage array/fabric layer to restore connectivity to host.
  
• Unmount NFS datastore
• Reboot all affected ESXi hosts to clear any residual references to the affected NFS device that was in the APD state
• Remount the NFS datastore

Additional Information

Refer to the KB article below for instructions on removing and remounting an NFS datastore:
Remounting a disconnected NFS datastore from the ESXi command line