Re: Often experiencing nfs server foo:/bar: not responding

On Mon, 19 Jun 2006, Scott Long wrote:

> David O'Brien wrote:
>
>> I am getting these errors all the time now (now being -CURRENT newer than 
>> Dec'05-Jan'06 time frame).  Are there some known issues in UDP or NFS 
>> serving since then?  This is on a virtually zero loaded 100Mbit network. 
>> Both the NFS server and client are FreeBSD-CURRENT systems.
>> 
>> I can trivially trigger this on all my FreeBSD-CURRENT NFS clients, simply 
>> by exiting Vim.  Did something change sometime in 2006 that would affect 
>> the default NFS mounts?
>
> A number of NFS changes happened in the first quarter of 2006, but they were 
> all focused on fixing existing bugs.  I've done extensive NFS client testing 
> with 6.1 and haven't seen anything unusual like you report, but I definitely 
> wouldn't rule out the possibility for accidental problems.  The best way to 
> start debugging this is to capture the packet stream with tcpdump; I always 
> run it in raw capture mode and then use other tools to analyze the output.

Another thing to try is to run a constant ping session in the background, and 
see if there are correlations between NFS errors and ping problems.  It's 
possible the origin of the issue is actually a network driver problem.

Robert N M Watson
Computer Laboratory
University of Cambridge