[PVFS-users] Re: PVFS access hangs

[Rob Ross]

Hi Murali,

I've fixed the initialization of lost_data; thanks!

Rob

On Fri, 16 Jul 2004, Murali Vilayannur wrote:

> Hi Rob,
> 
> Attached is a patch that fixes some I/O errors that I get when using PVFS1 
> from the latest CVS. It is somewhat related to the error scenario that you 
> mention below.
> The problem was that in function do_access() in iod/jobs.c, the variable
> lost_data is not initialized to 0, hence bad things happen below, when 
> a_p->u.rw.off et. al are updated. the job layer function i.e do_job()'s 
> return value is then interpreted as socket errors and the client socket is 
> closed. Hence clients see EPIPE's.
> 
>  In addition, the patch addresses some more cleanups that bring the 
> kpvfsd 
> code in synch. with some more recent changes that have come up recently.
> Hopefully, this will fix some of the errors that Brannen is noticing.
> Thanks,
> Murali
> 
> > That "empty job" message occurs when a client asks for a region of a file
> > and the server has no data in that region -- a common case would be trying
> > to read beyond EOF.
> > 
> > Are you sure that those messages are from the "cat" case below?  If they 
> > are, then they imply that some data was in fact getting to the iods from 
> > the client node.  But my first guess would be that that isn't happening.
> > 
> > Another thing that is possible is that somehow the IP addresses of your 
> > iods are not quite right?  For example, if you listed an address in the 
> > .iodtab that is accessible from the local node but not remotely, then you 
> > would have issues.  Can you send your .iodtab to us?  The pvfs-ping output 
> > too, in both cases?
> > 
> > > 	I could use pvfs-ping, pvfs-ls, etc (forgot to try u2p though)
> > > without a problem.  After mounting the pvfs filesystem I could use 'ls',
> > > etc.  However my test program hangs while trying to write files (though it
> > > can be interrupted).  I also tried to 'cat' one of the files, but that hung
> > > also (the last errors above are from that attempt).
> > 
> > What does your test program do, and what interface does it use?
> > 
> > Please do try u2p also if you have a chance, I'm guessing that it won't 
> > work.
> > 
> > > 	I'm using the Jan patch to pvfs-1.6.2, the two patches for redhat to
> > > the kernel code.  Not sure what else to try - I could set up one of the
> > > other two machines as the Manager and see what happens then - so far my
> > > experience has been that unless a machine is the Manager node, I cannot
> > > access the pvfs filesystem for read or write even though the utilities work
> > > fine.
> > 
> > I'm almost certain that you're seeing either a misconfiguration problem 
> > due to odd IP addresses in a PVFS config file, or a routing problem, or a 
> > firewall problem.
> > 
> > Regards,
> > 
> > Rob
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> > 
> >