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    <p>It looks to me like Python is just passing on an error from the underlying <code>open()</code> call and the real culprit here is the Linux CIFS support - I doubt Python would be synthesizing <code>ENOMEM</code> unless system memory was truly exhausted (and probably even then I'd expect the Linux <a href="http://blog.singhanuvrat.com/tech/the-linux-oom-killer" rel="nofollow">OOM killer</a> to be invoked instead of getting <code>ENOMEM</code>).</p> <p>Unfortunately it might need something of a Linux filesystem expert to figure out what's going on there, but looking at the <a href="http://lxr.free-electrons.com/source/fs/cifs/cifsfs.c" rel="nofollow">sources for CIFS in the Linux kernel</a>, I can see a variety of places where <code>ENOMEM</code> is returned when various kernel-specific resources are exhausted as opposed to total system memory, but I'm not familiar enough with it to say how likely any of them are.</p> <p>To rule out anything Python-specific you can run the process under <code>strace</code> so you can see the exact return code that Python is getting from Linux. To do this, run your command something like this:</p> <pre><code>strace -eopen -f python myscript.py myarg1 myarg2 2&gt;strace.log </code></pre> <p>The <code>-f</code> will follow child processes (i.e. the <code>jpeginfo</code> commands that you run) and the <code>-eopen</code> will only show you <code>open()</code> calls as opposed to all system calls (which is what <code>strace</code> does by default). This could generate a reasonable amount of output, which is why I've redirected it to a file in the above example, but you can leave it displaying on your terminal if you prefer.</p> <p>I would expect you'd see something like this just before you get your exception:</p> <pre><code>open("/path/to/file name.jpg", O_RDONLY) = -1 ENOMEM (Cannot allocate memory) </code></pre> <p>If so, this error is coming straight from the filesystem <code>open()</code> call and there's very little you can do about it in your Python script. You could catch the exception and retry (perhaps after a short delay) as you're already doing if <code>jpeginfo</code> fails, but it's hard to say how successful this strategy will be without knowing what's causing the errors in the first place.</p> <p>You could, of course, copy the files locally, but it sounds like that would be a serious pain as there are so many.</p> <p><strong>EDIT:</strong> As an aside, you'll expect to see lots of <code>open()</code> calls which are nothing to do with your script because <code>strace</code> is tracing <em>every</em> call made by Python, which includes it opening its own <code>.py</code> and <code>.pyc</code> files, for example. Just ignore the ones which don't refer to the files you're interested in.</p>
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    1. COWow, thanks for the detailed answer. I'll give that a go and see.
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    2. COI've done as you suggest but the strace log file is massive and i haven't had a chance to go through it yet. I've also rewritten my program to retry several times with a delay. The problems seem to resolve themselves after a half second delay. Thanks
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    3. COHaving looked throught the strace, it was the filesystem returning ENOMEM as you predicted. Thanks
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