vCenter is repeatedly reporting "An error occurred during host configuration: /usr/sbin/esxupdate returned with exit status: 15."

Products

• VMware vSphere ESXi
• VMware vCenter Server

Issue/Introduction

NFS datastores have become inaccessible or no longer visible in the vCenter.

Environment

vCenter Server
ESXi
NFS

Cause

Permissions for the volume (NFS export) that is backing the NFS Datastores are not set correctly.

Over a SSH session to the host, we may see that the datastores are mounted and accessible.
We may navigate into the NFS Datastore however, when attempt to list files (command ls), it returns Permission Denied

Log file /var/log/esxupdate.log file on the ESXi hosts will report the these missing datastores:
[####-##-##T##:##:##] esxupdate: 2101793: esxupdate: ERROR: An esxupdate error exception was caught:
[####-##-##T##:##:##] esxupdate: 2101793: esxupdate: ERROR: esxutils.EsxcliError: Errors:
[####-##-##T##:##:##] esxupdate: 2101793: esxupdate: ERROR: Error getting data for filesystem on '/vmfs/volumes/<datastore>': Cannot open volume: /vmfs/volumes/<datastore>, skipping.
[####-##-##T##:##:##] esxupdate: 2101793: esxupdate: ERROR: esximage.Errors.InstallationError: Failed to query file system stats: Errors:
[####-##-##T##:##:##] esxupdate: 2101793: esxupdate: ERROR: Error getting data for filesystem on '/vmfs/volumes/<datastore>': Cannot open volume: /vmfs/volumes/<datastore>, skipping.

Resolution

ESXi will need read, write and execute permissions on the volume (NFS export) that is backing the NFS Datastores.
Review permissions for the affected volumes and correct them.
Then, follow steps from the article Remounting a disconnected NFS datastore from the ESXi command line