Peter Pearson <pkpearson at nowhere.invalid> wrote:
> On Fri, 28 Sep 2018 15:01:41 +0100, Chris Green <cl at isbd.net> wrote:
> > Chris Green <cl at isbd.net> wrote:
> >> Brian Oney <brian.j.oney at googlemail.com> wrote:
> >> > Could you please try another tool like `convert'? E.g.
> >> >
> >> > $ convert 102_PANA/P1020466.JPG test.png
> >> >
> >> >
> >> > What does that say?
> >> Well, after having returned home with the laptop where this was
> >> failing and doing exactly the same thing again, it now works. However
> >> it did take several seconds before the >>> prompt appeared.
> >> The problem seems to be intermittent as I'm calling the function while
> >> importing images from a camera SD card and, sometimes, the import
> >> hangs but most times it works OK.
> >> I'll see if I can see anything common to when it hangs.
> > ... and the result is that it now hangs several images later in the
> > sequence! It's almost as if some resource is running out.
> > If I try convert on the 'problem' image it too hangs absolutely
> > solidly needing a 'kill -9'.
> > After some experimentation.... OK, it's some sort of file
> > accessibility problem between the SD card and the computer:-
> > Running 'convert 102_PANA/P1020493.JPG /tmp/xyz.png' hangs
> > So 'kill -9' the convert
> > Run 'cp 102_PANA/P1020493.JPG /tmp/fred' takes several seconds but returns
> If copying that particular file takes longer than copying other files,
> I'd start to suspect that it's stored in a failing spot in memory. Is
> 102_PANA/P1020493.JPG being read from a camera's flash memory? Does
> "convert" hang on /tmp/fred? Does 102_PANA/P1020493.JPG have an unusual
> size? Can you use smartctl to ask the storage device if it's
> encountering many errors?
Thanks, that sounds like a good explanation. The SD card has been in
use for quite a while so it might have some problems. I think I'll
retire it and see how things go.