Over the last week, I have been in the process of applying the latest patches to one of the VI3 environments I manage. While looking for potential problems I noticed that a single ESX server had lost access to all of its NFS datastores. All other VMs in the cluster, which connected to the same NFS datastores, appeared to be connected properly. I restarted the management services on the node hoping to fix the issue and continue with the upgrade. Unfortunately, restarting the management services had no effect (remember while restarting the management services should be one of the first steps and does solve a lot of VMware issues, it is not the only step). I verified that the host was configured properly and that no configuration changes had recently taken place. I also had the networking team verify that the switch ports were configured properly.
All checks came back normal, so what was going on?