Backup of VMs on NFS Storage fail with Error: "NFC Error 11"

Products

• VMware
• VMware vCenter Server
• VMware vSphere ESXi

Issue/Introduction

Symptoms:

• Third-party backup software that uses the vSphere API (VDDK) fails to connect to vmdk of VMs when NBD mode is in use.
• In the logs of, Veritas backup you see errors similar to:
  <YYYY-MM-DD>T<time> - Error bpbrm (pid=69670) from client FQDN: ERR - Error opening the snapshot disks using given transport mode: nbd Status 23</time>
<YYYY-MM-DD>T<time> - Critical bpbrm (pid=69670) from client FQDN: FTL - cleanup() failed, status 6</time>
• In hostd.log you see errors similar to:
  <YYYY-MM-DD>T<time> : g_vixInterfaceLogger:libvix.cpp:1801 <DEBUG> : [VFM_ESWARN] [NFC ERROR] NfcFssrvrProcessErrorMsg: received NFC error 11 from server: NfcFssrvrOpen: permission check failed for file [F8200-A4-C1-N2-NFS-WIN-PROD-SILBER] datastore_name/vm_name-00000x.vmdk, access = 1</time>

Environment

VMware vSphere ESXi 7.0.x  

VMware vSphere ESXi 6.0.x

VMware vCenter Server Appliance 6.0.x

VMware Update Manager 6.0

VMware vCenter Converter Standalone 6.x

VMware vCenter Server 6.0.x

Resolution

The error is because of an issue with the NFS storage. To workaround:

1. Ensure the NFS storage is configured as per the recommendations
2. Disconnect and re-connect to the NFS Storage to create a new session between ESXi Host and NFS Storage

 

Additional Information

For details on the recommendation on NFS storage see:

• Create NFS Datastore in the vSphere Client
• NFS Protocols and ESXi
• Guidelines and Requirements for NFS Storage with ESXi