Problem with file locking on nfs mounted filesystem

Problem with file locking on nfs mounted filesystem

Post by Leonard Even » Thu, 14 Oct 1999 04:00:00



This started with a problem with Maple which we have on a file
system which is nfs mounted from a server.  This worked fine
until recently, but now on some of our systems, maple has
a problem when invoking help.  We've isolated the problem
so that it no longer is specifically a maple problem except
that for some odd reason maple is trying to lock the help
file.

What happens is the following.  We are running RH6.0 on our
server with a 2.2.12 kernel and the knfsd-1.2.2-4 nfs server
package.  From machines running RH5.2 and kernels 2.0.36 or earlier,
we appear to be able to lock files in the nfs mounted directory
using a fcntl call.  But on machines running  RH.6.X and more
up to date kernels, we can't.  However, for a directory
mounted from another server, running  RH6.0 and a 2.2.5 kernel, we
can lock files.

Can anyone enlighten us as to what is going on?

--


Dept. of Mathematics, Northwestern Univ., Evanston, IL 60208

 
 
 

1. ksh hangs attempting to lock history file on NFS mounted file system

We have a bunch of Unixware users, mostly running 1.1.4, who are having
this problem (ksh hangs, investigation shows it is in the process of
trying to lock the history file)

I have offered them this workaround:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

There is a ksh bug that causes ksh to hang when a user has multiple shell
processes trying to share a history file in a NFS mounted directory, e.g.
the user's home  directory.

Recommended fix: use this line in .profile:

    HISTFILE=/tmp/.history.$$; export HISTFILE

This causes a different history file to be created for each process.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

I use this myself all the time and have never experienced the problem.
I prefer to have a separate history for each process, but some of our
users here really like to have one big history file shared by all
processes.

Is there a Unixware 1.1 patch for this?

--

Computing and Telecommunications Services       Unix System Administration Team
http://info.dr.att.com/~ambient/home.html       303-538-4821

Internet User #19075 of the Citizens Internet Empowerment Coalition
See http://www.cdt.org/ciec.

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