There is any way to list processes' I/O usage? I'm not interested in overall I/O statistic, vmstat and sar already do that for me. It seems there is a lack of commands to get process level detail I/O. What I'm looking for is someting like:

# ps aux | head -1 ; ps aux | tail +2 | sort -nrk3 | head
USER PID %CPU %MEM SZ RSS TTY STAT STIME TIME COMMAND
root 73764 5.3 0.0 384 384 - A Aug 26 3018:25 wait
root 471150 5.2 23.0 1871336 1874984 - A 17:19:50 414:31 dsmserv quiet
root 65568 5.2 0.0 384 384 - A Aug 26 2919:28 wait
root 57372 5.2 0.0 384 384 - A Aug 26 2918:16 wait
root 8196 4.9 0.0 384 384 - A Aug 26 2753:25 wait
root 69666 4.8 0.0 384 384 - A Aug 26 2705:49 wait
root 61470 4.8 0.0 384 384 - A Aug 26 2721:21 wait
root 77862 4.6 0.0 384 384 - A Aug 26 2618:47 wait
root 53274 4.5 0.0 384 384 - A Aug 26 2541:19 wait
root 229536 3.5 0.0 984 972 - A Aug 26 1957:23 /usr/sbin/portma

...but for I/O, not CPU. Thanks in advance!

have you tried the lsof utility?

Does iotop do what you want?

Whoops, didn't notice this was in an AIX forum...you may not have iotop available to you. Not that its installed by default in many Linux distros, either.