how to monitor connection to NFS mount

Question

I primarily work on files that lie on an NFS mounted network share. Since a recent IT upgrade, the network connection to this NFS mount seems sketchy -- every day, a couple of times during my work, I lose connectivity for a couple of seconds, causing programs to freeze or shut down, error messages like "cannot find file" when I try to save files with modifications that are open in my IDE, etc.

IT support are asking for detailed error reports before they start fixing the problem, which I cannot give them beyond "I couldn't save/copy/write this file, and then 10 seconds later I could" at the moment.

My questions are

1. is there a logging utility that I can leave running in the background to monitor the connection to the NFS mount (can i get nfsiostat or icpld to do what I need, for example?) so i can just send the log to IT support after I encounter this issue for them to examine?
2. how would I set up such a logger so that it contains enough / the right kind of info for them to figure out the issue?

Answer 1

It's a bit weird that you need to give proof that something is wrong but anyway, it seems to be a fact of life, so: depending on what you want/need/know, you could:

1. These two together:

   • ping -D -i 2 1.2.3.4 > /var/log/ServerName.log in one minimised terminal and tail --follow /var/log/ServerName.log in the other. The first couple of hours when something goes wrong have a look and see whether it's network-related or not.

   AND

   • A script, running on your local machine that renames a file every 2 seconds on one of your NFS directories and logs the times when it cannot.

     #!/bin/bash    
     while true 
     do
       mv /szNFSMount/TestFile.1 /szNFSMount/TestFile.2
       if [ $? -ne 0 ]; then
         echo $(date) >> /var/log/NFSMount.log
       fi
       sleep 2
       mv /szNFSMount/TestFile.2 /szNFSMount/TestFile.1
       if [ $? -ne 0 ]; then
         echo $(date) >> /var/log/NFSMount.log
       fi
       sleep 2
     done
     

Why these two together? ping is extremely low level: data link layer and the other one is extremely high level: Application layer. Together they make for unrefutable proof.

2. Do NFS debugging... It's tricky stuff and you need to have root access to your own machine. Do you???