diff -up nfs-utils-1.3.0/tools/nfs-iostat/nfs-iostat.py.orig nfs-utils-1.3.0/tools/nfs-iostat/nfs-iostat.py

--- nfs-utils-1.3.0/tools/nfs-iostat/nfs-iostat.py.orig	2017-11-03 09:29:39.000000000 -0400

+++ nfs-utils-1.3.0/tools/nfs-iostat/nfs-iostat.py	2017-11-03 09:34:25.000000000 -0400

@@ -434,6 +434,8 @@ def parse_stats_file(filename):

         words = line.split()

         if len(words) == 0:

             continue

+	if line.startswith("no device mounted") :

+            continue

         if words[0] == 'device':

             key = words[4]

             new = [ line.strip() ]