Thanks for your answer, it explains a lot. I thought this was possible because it's possible using LSF without MPI, but I guess not. Thread closed?
Thanks, Michal Zielinski On Tue, Sep 9, 2014 at 11:22 AM, Chrysovalantis Paschoulas < c.paschou...@fz-juelich.de> wrote: > Hi! > > The answer to your question is no, it is not possible. > > A task (Linux process) is running on a single node only and can > allocate/use only the available CPUs on that node. You need an MPI job (or > Hybrid MPI+OpenMP) in order to utilize CPUs on different nodes for a single > purpose/application. > > Best Regards, > Chrysovalantis Paschoulas > > > On 09/09/2014 05:14 PM, Michal Zielinski wrote: > > Phil, > > I believe that 1 core per node is correct. > > Maybe let me ask this first: is possible for a single task to use > specific CPUs across several nodes? > > Thanks, > Mike > > On Tue, Sep 9, 2014 at 10:38 AM, Eckert, Phil <ecke...@llnl.gov> wrote: > >> Mike, >> >> In your slurm.conf you have Procs=1, (which is the same as CPUS=1) and >> Sockets (if ommited will be inferred from CPUS, default is 1) and >> CoresPerSocket (default is 1) >> >> So at this point the slurm.conf has a default configuration of 1 core >> per node. >> >> Phil Eckert >> LLNL >> >> From: Michal Zielinski <michal.zielin...@uconn.edu> >> Reply-To: slurm-dev <slurm-dev@schedmd.com> >> Date: Tuesday, September 9, 2014 at 6:35 AM >> To: slurm-dev <slurm-dev@schedmd.com> >> Subject: [slurm-dev] Re: "Requested node configuration is not available" >> when using -c >> >> Josh, >> >> I believe that *-n *sets the number of tasks. I only want a single >> task, as when a single process uses multiple cores. *srun -n 2 hostname* >> returns >> >> linux-slurm2 >> linux-slurm3 >> >> which is definitely not what I want. >> >> Thanks, >> Mike >> >> >> On Mon, Sep 8, 2014 at 8:07 PM, Josh McSavaney <mcsa...@csh.rit.edu> >> wrote: >> >>> I believe your slurm.conf is defining 4 nodes with a single logical >>> processor each. You are then trying to allocate two CPUs on a single node >>> with srun, which (according to your slurm.conf) you do not have. >>> >>> You may want to consider `srun -n 2 hostname` and see where that lands >>> you. >>> >>> Regards, >>> >>> Josh McSavaney >>> Bit Flipper >>> Rochester Institute of Technology >>> >>> >>> >>> On Mon, Sep 8, 2014 at 7:42 PM, Christopher Samuel < >>> sam...@unimelb.edu.au> wrote: >>> >>>> >>>> On 09/09/14 07:26, Michal Zielinski wrote: >>>> >>>> I have a small test cluster (node[1-4]) running slurm 14.03.0 setup >>>>> with >>>>> CR_CPU and no usage restrictions. Each node has just 1 CPU. >>>>> >>>> [...] >>>> >>>>> But, *srun -c 2 hostname* does not work, and it returns the above >>>>> error. >>>>> >>>>> I have no idea why I can't dedicate 2 cores to a single job if I can >>>>> dedicate each core individually to a job. >>>>> >>>> >>>> What does "scontrol show node" say? >>>> >>>> cheers, >>>> Chris >>>> -- >>>> Christopher Samuel Senior Systems Administrator >>>> VLSCI - Victorian Life Sciences Computation Initiative >>>> Email: sam...@unimelb.edu.au Phone: +61 (0)3 903 55545 >>>> http://www.vlsci.org.au/ http://twitter.com/vlsci >>>> >>> >>> >> > > > > > ------------------------------------------------------------------------------------------------ > > ------------------------------------------------------------------------------------------------ > Forschungszentrum Juelich GmbH > 52425 Juelich > Sitz der Gesellschaft: Juelich > Eingetragen im Handelsregister des Amtsgerichts Dueren Nr. HR B 3498 > Vorsitzender des Aufsichtsrats: MinDir Dr. Karl Eugen Huthmacher > Geschaeftsfuehrung: Prof. Dr.-Ing. Wolfgang Marquardt (Vorsitzender), > Karsten Beneke (stellv. Vorsitzender), Prof. Dr.-Ing. Harald Bolt, > Prof. Dr. Sebastian M. Schmidt > > ------------------------------------------------------------------------------------------------ > > ------------------------------------------------------------------------------------------------ > >
