Use the TMP directory to run your Cray programs

Try the command df, you'll get a listing something like: 

 df
Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/dsk/rootb         1600000    336180   1263820  22% /
/dev/dsk/tmp         117928576    553472 117375104   1% /tmp
/dev/dsk/usrb          1760000    727840   1032160  42% /usr
/dev/dsk/srcb           600000    451240    148760  76% /usr/src
/dev/dsk/newopt        1760000    577376   1182624  33% /opt
/dev/dsk/home           600000    469592    130408  79% /local
/proc                 33494508    197244         0 100% /proc
Our files are in /local (next to last row). The blocks allocated for /tmp is much larger (the value in the second column) than the blocks allocated for /local. We should be running the executables of our programs (a.out) from the /tmp directory. Program execution is faster in /tmp directory, plus we'll be saving space in /local.

  1. Create a directory in /tmp for yourself: mkdir /tmp/myusername
    NOTE: ALL USERS HAVE ACCESS TO THIS /tmp DIRECTORY.

  2. To compile: cc myprog.c -o /tmp/myusername/myprog
    or if you like using a.out: cc myprog.c -o /tmp/myusername/a.out

  3. To run your program: mpirun -np 4 /tmp/myusername/myprog
    or if you're using a.out: mpirun -np 4 /tmp/myusername/a.out

  4. Periodically check your files for core (this is a coredump from a crashed program run): ls -l will show a large file named core. Delete this file: rm core

  5. df can show if our space in the /local directory is filling up.