[PVFS-developers] Re: [PVFS-users] Recompile pvfs module for SuSE 2.4.19-NUMA

[Rob Ross]

Hi Claude,

Sorry we didn't get back to you sooner.  I'm glad that the kernel update 
fixed the problem.

What block size (bs=XXX) are you using in your tests?

Note that when reading no I/O can start until data is read off disk, while 
in the write case data can start moving right away.  So you may just be 
seeing startup costs.

You could look at increasing TCP buffer sizes on your system as a first 
step.

Regards,

Rob

On Mon, 8 Mar 2004, Claude Pignol wrote:

> Greetings,
> 
> An upgrade to 2.4.21 fixes the problem.
> Compile and start OK.
> I have noticed a performance problem in reading from PVFS.
> With big I/O (few MB) reading is around 1/3 of the performance of writing.
> Pvfs deamons with default parameters
> Reading/Writing from on node to pvfs using dd.
> I have verified the disk performance of all the 10 I/O nodes
> I have also verified the network perf to all the nodes.
> What is the best strategy/tools to address this kind of problem?
> Thanks
> 
> 
> Claude Pignol wrote:
> 
> > Greetings,
> >
> > I try to do a benchmark of pvfs with the SuSE 2.4.19-NUMA kernel
> > to compare with the SuSE 2.4.19-SMP kernel.
> > No problem to compile and load the pvfs.o module with the SMP kernel
> >
> > With the NUMA kernel I get 3 undefined symbols when I try to load the 
> > module
> > pvfs.o: unresolved symbol __pollwait
> > pvfs.o: unresolved symbol mem_map
> > pvfs.o: unresolved symbol iget4
> >
> > The kernel source is installed.
> > Any idea?
> > Thanks in advance
> > Claude
> >
> >
> > _______________________________________________
> > PVFS-users mailing list
> > PVFS-users at www.beowulf-underground.org
> > http://www.beowulf-underground.org/mailman/listinfo/pvfs-users
> >
> 
> 
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