lsof / > lsof_1.txt; sleep 15; lsof / > lsof_2.txt; sdiff -w250 lsof_1.txt lsof_2.txt > lsof_difference.txt; cat lsof_difference.txt | egrep '\||<|>'

This can take long:
touch new_file
find / -newer new_file -not -path "/proc/*" -exec ls -lh {} \;

Or just using iotop this way, monitor online:
iotop -Pbktoqqq -d 3