--- In Jason Stahls <> wrote:
>
> j.chitte wrote:
> > One remaining headache is files being written by the SBC don't seem to be
> > updated when read back by the same. This is critical for the control
> > software.
> >
> > I write out some ADC values to a file under htdocs then it gets read back
> > in by a control loop. When I'm running on nfs these files always give the
> > same content when read.
> >
> > If I look at the file from the nfs server end it updates correctly so on
> > disk it is good. From the arm end it's meta-data get updated correctly but
> > the content always gives what is was when mounted. Either from using 'cat'
> > or when read programatically.
> >
> > Can anyone make sense of that.
>
> That's another nfs headache I remember :) As I remember the nfs client
> is caching the read data on you and not asking for the updated file from
> the server. Again, unsure how I fixed it but this might point you in
> the right direction...
>
> --
> Jason Stahls
>
Thanks for your comments.
I found the problem in fstab on the board. I had a nfs mount in the other
direction that was getting pulled in by 'mount -a' during boot-up.
The mount was not showing up in mount output that's why I missed it but it
seems it caused this problem before failing.
so humble apologies to the nfs team and much relief to me , I was really
starting to doubt how reliable nfs was.
My control loop is now doing what it should.
/js
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