Very quick update …
Many readers will be aware of an ongoing issue with NFS in ESXi 5.5U1. My colleague, Duncan, wrote an article about it on his blog site recently entitled – Alert: vSphere 5.5 & NFS issue. Essentially, your NFS datastore may experience an APD (All Paths Down) condition. The issue is also described in KB article 2076392.
I’m pleased to say that VMware has now produced a patch to address this issue. The patch is 5.5EP4 (June 2014) and can be downloaded from VMware’s patch repository site here and will address this issue. Search on ESXi (Embedded and Installable), version 5.5.0. Another KB article, 2077360, has more information about the patch fix.