We run a script with the following directive once per month to delete validation log files after 60 days. They are hard to get to and are usually irrelevant when they succeed. The script freed about 250MB of space this month.
find /ITG/$1/logs/VAL_* -mtime +60 -type f -print 2>&1 | tee -a /tmp/ITGmaint | xargs rm -f 2>&1
We also have deleted old reports manually. If anyone has a method of automating this process, we would be very interested.