[778] in linux-net channel archive
Re: Strange behaviour with NFS
daemon@ATHENA.MIT.EDU (Donald Becker)
Wed Jul 26 14:01:48 1995
Date: Wed, 26 Jul 95 00:15:09 EDT
From: becker@cesdis1.gsfc.nasa.gov (Donald Becker)
To: linux-net@vger.rutgers.edu
>From: joey@finlandia.Infodrom.North.DE (Martin Schulze)
>Subject: Strange behaviour with NFS
>I found some strange behaviour according to the nfs filesystem in the
>kernel.
>
>Whenever the nfs server isn't reachable the process on the client
>machine just hangs around, partially in 'D' status which means
>non-interruptable.
I also encountered this problem today. This bug hung a few nodes on our
Linux cluster. Luckily one still had a few process slots left to figure to
do a 'ps'. Here a few notes:
1. The processes were in the 'D' disk-wait state. Most were
swapped out.
2. The processes counted toward the load average, but didn't consume
CPU time. The load average on the still-working machine was >35.
3. Doing 'kill -1' and 'kill -9' had no effect. The processes
didn't even turn into zombies.
The problem apparently started when a few NFS serving nodes were
unavailable. I assume NFS clients might have timed out. Even when the
servers were returned to service the processes were still hung.
Donald Becker becker@cesdis.gsfc.nasa.gov
USRA Center of Excellence in Space Data and Information Sciences.
Code 930.5, Goddard Space Flight Center, Greenbelt, MD. 20771
301-286-0882 http://cesdis.gsfc.nasa.gov/pub/people/becker/whoiam.html
