Cbb/Baobab

The Baobab Cluster

CBB's internal cluster.

The new cluster is made up of 6 nodes with 24 cores and 64 GB RAM on each node.

To use the baobab cluster setup your environment to use mpi. I generally recommend you add this to your CBB .bashrc file before you get started.

if [ ! -z `hostname | grep baobab` ]; then
  module add mpi/openmpi-x86_64
fi

Another recommendation is to create an ssh key pair for yourself, if you don't already have one. If your jobs are not running this is probably the reason why.

cd .ssh
ssh-keygen -t dsa
<enter><enter><enter> [just take the defaults and DON'T set a pass phrase]
cat id_dsa.pub >> authorized_keys

After you have done this, you can ssh to the baobab headnode. You can do this from any machine connected to the internal CBB network.

ssh baobab.cbb.lan

Add the node hostkeys to your known_hosts (Only needs done once)

pdsh -w baobab-[1-6] "uptime"

Please use the PBS submission system to run your jobs. Here is a quick rundown of what you will need to know.

Make yourself a PBS submission script like the following:

#PBS -l nodes=6:ppn=24,walltime=00:01:00
## nodes = total number of nodes you need
## ppn = processors per node that you will need
## walltime = amount of time your job will be allowed before being forcefully removed
#####################################################################################
cd $PBS_O_WORKDIR
## How many cores total do we have?
NO_OF_CORES=`cat $PBS_NODEFILE | egrep -v '^#'\|'^$' | wc -l | awk '{print $1}'`
##
## Main execution
echo "Job Started at: `date`"
mpiexec -np $NO_OF_CORES -machinefile $PBS_NODEFILE hello
echo "Job Ended at: `date`"

To submit the jobs to the cluster from the headnode:

qsub <yoursPBSscript>

To check the status of your jobs:

qstat -a

To delete your jobs from the queue:

qdel <Job_Number/Identifier>

For more examples look here: https://wiki.cs.vt.edu/wiki/Cbb/Baobab/examples