- Log onto the cray using your account: ssh username@cray2.colostate.edu
- File Storage. The files in the home directory are backed up. Keep all your files there. To execute paralel program you need to be in the lustrefs directory. (You have one provided.) Also, Large files should be stored in lustrefs directory. Lustrefs is not backed up. It is best to store executables and their input output data in lustrefs, and copy anything valuable back to your home directory.
- Transferring files from your computer onto CRAY home directory
Execute this command from your computer.
scp "file-to-be-transferred" "personnel-id"@cray2.colostate.edu:"destination-directory"
- Compilers on the Cray.
The Cray user guide version 3 was used as reference
for the information below. The default compiler loaded is the cray compiler.
There are only a few licenses for this compiler, so we use the gcc compiler
suite. Use the following command to swap to gcc
module list
module swap PrgEnv-cray PrgEnv-gnu
Use the Makefile to compile your codes.
- Executing your program on a login node.
Move the code to your lustrefs directory, and execute it using the aprun command
as follows:
mv program lu*
cd lu*
aprun -n1 -d1 program
Check "man aprun" for aprun options. The -n option specifies the number of times (spawns) of "program". The -d option (used for openMP specifies the number of cores
executing the code in a node.
- Executing your program on a compute node.
You will need to write a short bash script.
#!/bin/bash
#PBS -N PA1
#PBS -j oe
#PBS -l mppwidth=2
#PBS -l walltime=00:01:00
#PBS -q small
cd /home/[username]/lustrefs/PA1
export OMP_NUM_THREADS=2
aprun -n1 -d2 ./jacobi_1D 4000 200000
Save this to a file and then on the command line run:
qsub filename
qstat -a will show you the current state of the queue.