Ideally, CCDBIG should be run on a machine which is not heavily loaded, and furthermore one which is not being used for important processes. The latter is desirable, because if the CCDPACK applications are being tested to destruction then at the least they will cause heavy swapping between memory and disk, which dramatically degrades performance of the machine (particularly interactive response time), and they can sometimes lead to termination of other processes and even system crashes.
To run the script, the recommended procedure is to change to an empty directory, on a local disk with ample free space, and then:
% cp $CCDBIG_DIR/ccdbig .
(edit ccdbig as required)
CCDBIG: assessing CCDPACK resource usage for large data sets