show excesive IO in disk

disk.bash

iotop -bktoqqq -d .5

where: -b     is batch mode
       -k     is kilobytes/s
       -t     adds timestamp
       -o     only show processes or threads actually doing I/O
       -qqq   removes output headers
       -d .5  updates every .5 seconds
Once you have the process id, you can also find the files with

 lsof -p $PID

iotop -aoP

-a Will show accumulated output
-o Will only output
-P Will only show processes instead of threads