When I tried on different machines I got better results but again worse than one execution. Results are given below. So file access performances decrease linearly with the number of accesses. Is there a configuration that will make pvfs2 scale better for concurrent accesses? Why pvfs2 behave like this?
-- GROUP - 1--- time -p ./write /pvfs2/t1 100 => 26.44 [executed on master] time -p ./write /pvfs2/t2 100 => 26.72 [executed on master] time -p ./write /pvfs2/t3 100 => 26.57 [executed on master] --- GROUP - 2--- time -p ./write /pvfs2/t4 100 => 17.69 [executed on node1] time -p ./write /pvfs2/t5 100 => 17.55 [executed on node2] time -p ./write /pvfs2/t6 100 => 16.91 [executed on node3] --- GROUP - 3--- time -p ./write /pvfs2/t7 100 => 9.42 [executed on master] --- GROUP - 4--- time -p ./write /pvfs2/t8 100 => 9.12 [executed on node1] --- GROUP - 5--- time -p ./read /pvfs2/t4 ./t4 => 26.17 [executed on master] time -p ./read /pvfs2/t5 ./t5 => 27.00 [executed on master] time -p ./read /pvfs2/t6 ./t6 => 26.92 [executed on master] --- GROUP - 6--- time -p ./read /pvfs2/t4 ./t4 => 14.64 [executed on node1] time -p ./read /pvfs2/t5 ./t5 => 16.62 [executed on node2] time -p ./read /pvfs2/t6 ./t6 => 15.55 [executed on node3] --- GROUP - 7--- time -p ./read /pvfs2/t4 ./t4 => 9.89 [executed on master] --- GROUP - 8--- time -p ./read /pvfs2/t4 ./t4 => 10.02 [executed on node1] On 11/22/05, Rob Ross <[EMAIL PROTECTED]> wrote: > The numbers make absolute sense for four executions on the same machine. > > Rob > > Hamza KAYA wrote: > > Yes. I'll try them on different machines too. I'll inform you as soon > > as possible. > > Thanks very much. > > > > -- > > Hamza > > > > On 11/21/05, Rob Ross <[EMAIL PROTECTED]> wrote: > > > >>Hi, > >> > >>Are you running all those processes on the same machine? > >> > >>Rob > >> > >>Hamza KAYA wrote: > >> > >>>Thanks very much. Another problem I observed is about simultaneous > >>>accesses. Normally a copying a 100MB file to pvfs takes approximately > >>>10secs. in my system. > >>> > >>>time -p ./copy testfile /pvfs2/testfile -> 9.76sec. > >>> > >>>However copying 4 files simultaneously gives the following results: > >>>time -p ./copy testfile1 /pvfs2/testfile1 -> approx. 36sec. > >>>time -p ./copy testfile2 /pvfs2/testfile2 -> approx. 36sec. > >>>time -p ./copy testfile3 /pvfs2/testfile3 -> approx. 36sec. > >>>time -p ./copy testfile4 /pvfs2/testfile4 -> approx. 36sec. > >>> > >>>[here 'copy' is a programme which uses the system calls. However same > >>>result occurs while using coreutils 'cp' and a simple program which > >>>makes consecutive fread and fwrite calls.] > >>> > >>>All of the files used are 100MB. And most of the operations > >>>overlapped. Another point is the CPU consumption of pvfs2-client-co. > >>>When multiple accesses to one file occurs, it consumes approx. %40 of > >>>the CPU. > >>>e.g. > >>> cp /pvfs2/test test1 > >>> cp /pvfs2/test test2 > >>> cp /pvfs2/test test3 > >>> cp /pvfs2/test test4 > >>> > >>>What may be the problem? Or is this situation is a problem? > >>>Thanks, > >>> > >>>-- > >>>Hamza > >>> > >>>On 11/18/05, Robert Latham <[EMAIL PROTECTED]> wrote: > >>> > >>> > >>>>On Thu, Nov 17, 2005 at 05:08:45PM +0000, Number Cruncher wrote: > >>>> > >>>> > >>>>>I noticed Rob's post at > >>>>>http://lists.gnu.org/archive/html/bug-coreutils/2005-11/msg00068.html > >>>>>which discusses a patch to cp. Has this been accepted? Where can I get a > >>>>>copy (excuse the pun!) > >>>> > >>>>The attached patch, based largely on earlier efforts by Neill Miller, > >>>>to coreutils CVS will make copy behave better with pvfs2. > >>>>Unfortunately, this patch also modifies lib/Makefile.am, so you'll > >>>>need fairly recent versions of autotools/automake/autowhatever. It > >>>>should apply ok against coreutils-5.92 > >>>> > >>>>I don't know if this will make it into coreutils-6.0, but i'll keep > >>>>bugging the maintainers... > >>>> > >>>>==rob > >>>> > >>>>-- > >>>>Rob Latham > >>>>Mathematics and Computer Science Division A215 0178 EA2D B059 8CDF > >>>>Argonne National Labs, IL USA B29D F333 664A 4280 315B > >>>> > >>>> > >>>>_______________________________________________ > >>>>PVFS2-users mailing list > >>>>[email protected] > >>>>http://www.beowulf-underground.org/mailman/listinfo/pvfs2-users > >>>> > >>>> > >>>> > >>>> > >>> > >>> > >>>_______________________________________________ > >>>PVFS2-users mailing list > >>>[email protected] > >>>http://www.beowulf-underground.org/mailman/listinfo/pvfs2-users > >>> > >> > > > _______________________________________________ PVFS2-users mailing list [email protected] http://www.beowulf-underground.org/mailman/listinfo/pvfs2-users
