[PVFS-users] u2p failure to open destination file

[Rob Ross]

Hi,

Please try the recently released patch for 1.6.2; this should fix the 
problem.

Regards,

Rob

On Sun, 25 Jan 2004, David J Glaze wrote:

> Hello All,
> 
> I'm having some problems with an installation of PVFS on a group
> of Gentoo Linux machines (that were all RedHat 7.3 machines about
> a month ago).  Everything worked very well under RedHat with PVFS 
> versions up to 1.6.0.  I'm using 1.6.2 now.
> 
> My first problem is with 'u2p', which I was using for some crude
> performance tests.  Observe:
> 
> -----------------------------------------------------------------
> # ls -l /scratch/athlon/test
> total 102400
> -rw-r--r--    1 root     root     104857600 Jan 25 17:45 100MB.1
> 
> # u2p /scratch/athlon/test/100MB.1 /scratch/athlon/test/100MB.2
> pvfs_open: unable to open destfile /scratch/athlon/test/100MB.2
> 
> # cp /scratch/athlon/test/100MB.1 /scratch/athlon/test/100MB.2
> 
> # ls -l /scratch/athlon/test
> total 204800
> -rw-r--r--    1 root     root     104857600 Jan 25 17:45 100MB.1
> -rw-r--r--    1 root     root     104857600 Jan 25 18:05 100MB.2
> 
> #
> -----------------------------------------------------------------
> 
> This PVFS filesystem is mounted at /scratch/athlon, and the 
> above commands were executed on the mgr node.  The 'u2p' command
> works fine if the destination is not in the PVFS filesystem.  
> 
> I'm executing the above commands as root, but regular users have 
> the same problem.  There are no messages in the system logs upon 
> the above failure.  I did an 'strace' of the above u2p command,
> but I didn't see anything obviously wrong.  For the morbidly 
> curious, I have the (long) strace output here:
> http://ristretto.ecn.purdue.edu/~glaze/tmp/u2p.strace
> 
> This is a fairly generic installation with 16 iod nodes and a 
> separate mgr node (named 'ristretto.ecn.purdue.edu' in the strace
> output), all connected through a private 100Mbps network with a 
> gigabit uplink to the mgr node, which then connects to the other
> cluster subnets and the rest of the world.  I can provide any 
> of the various config files upon request.
> 
> All machines are using a plain-vanilla unpatched 2.4.24 kernel and
> glibc 2.3.2.
> 
> Am I doing something braindead here?  Are there any nice tools
> or techniques I'm unaware of to help diagnose this problem?  (Yes,
> I know I can dig through the source and attack the problem with a 
> debugger, but I don't have much time for that at the moment.  I was
> hoping someone had seen this before.  :-)
> 
> On another note...  My second problem is that the PVFS read/write
> speed seems to be about an order of magnitude slower under Gentoo 
> than under RedHat.  I'm still trying to diagnose this one, so I'll
> save it for another post when I know more.  (I'm actually hoping 
> that the above u2p problem is somehow related to the performance 
> issue.)
> 
> Thanks!
> 
> Dave
> 
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