title: SLURM error: sbatch: error: Batch job submission failed: Requested node configuration is not available
body: <p>I'm trying to use a cluster to run an MPI code. the cluster hardware consist of 30 nodes, each with the following specs:
  16 Cores at 2 Sockets (Intel Xeon e5-2650 v2) - (32 Cores with multithreading enabled)
  64 GByte 1866 MT/s main memory
  named: aria</p>
  
  <p>the slurm config file is as following:</p>
  
  <pre><code>#SBATCH --ntasks=64                     # Number of MPI ranks
  #SBATCH --cpus-per-task=1               # Number of cores per MPI rank
  #SBATCH --nodes=2                       # Number of nodes
  #SBATCH --ntasks-per-node=32             # How many tasks on each node
  #SBATCH --ntasks-per-socket=16          # How many tasks on each CPU or socket
  #SBATCH --mem-per-cpu=100mb             # Memory per core
  </code></pre>
  
  <p>when I submit the job, a return message comes out with the following content: sbatch: error: Batch job submission failed: Requested node configuration is not available
  which is a little bit confusing. I'm submitting one task per a cpu and dividing the tasks equally between nodes and sockets, can anyone please advise on the problem with the aforementioned configs? and one more thing: what is the optimum configuration given the hardware specs?</p>
  
  <p>Thanks in advance</p>