On Tue, Nov 29, 2016 at 11:37 AM, Tom Horsley <horsley1953@gmail.com> wrote:
On Tue, 29 Nov 2016 10:05:15 -0500
bruce wrote:

> On the clientside easy enough to automate a process/logic to every so
> often do a umount/remount process on the individual client.

Automounter.
 

That will work, but it is pretty heavy handed, and "umount -l"
is almost always necessary because something, somewhere, on the
system is always referencing the remote file and it will refuse
a normal "umount" (and umount -f has to time out for hours before
it forces the unmount).

It may be worthwhile tracking down the reasons remote files are being
held open.  Sometimes it is just sloppy habits of users who leave buffers
active in emacs and sometimes there are config files that can be
moved to the client.
 
I get this crap all them time when a symlink changes on the
server, and the client doesn't see the change (which isn't supposed
to be a problem, but is). Usually removing the symlink, doing
an "ls -lL' on the client to convince it that it is gone,
then recreating it on the server works.

I've never been able to understand how it is that NFS is so
widely used, yet so broken.

Your breakage is another person's feature.

When NFS over UPD appeared on the CDC mainframe at work, I started
a job on a 7/24 client to write a timestamp to the server every 30 mins.  
Clients were vaxen and a few unix workstations.

Over a  couple years, I never lost a timestamp that was generated
on the client.  This was thru crashes on the server, etc. 

Whenever the server or network went down, all the clients would
hang as soon as something tried to touch the server, and clients
trying write "too much" data would run out of buffer space.

A few years later, VMS was being replaced by UNIX and NeXT and
automounters were a big help reducing the number of times times
clients would hang on a not-responding NFS server.

Today, in a typical research lab environment lab with Windows and
linux and macOS workstations, the linux and macOS users like it that
they just need to be logged on their workstation to get automounted
NFS shares, while SMB/CIFS require that they provide credentials at
mount time.   

--
George N. White III <aa056@chebucto.ns.ca>
Head of St. Margarets Bay, Nova Scotia