[t@bjb0541 ~]$ sudo iotop --help

Usage: /sbin/iotop [OPTIONS]

DISK READ and DISK WRITE are the block I/O bandwidth used during the sampling

period. SWAPIN and IO are the percentages of time the thread spent respectively

while swapping in and waiting on I/O more generally. PRIO is the I/O priority at

which the thread is running (set using the ionice command).

Controls: left and right arrows to change the sorting column, r to invert the

sorting order, o to toggle the --only option, p to toggle the --processes

option, a to toggle the --accumulated option, i to change I/O priority, q to

quit, any other key to force a refresh.

Options:

--version show program's version number and exit

-h, --help show this help message and exit

-o, --only only show processes or threads actually doing I/O

-b, --batch non-interactive mode

-n NUM, --iter=NUM number of iterations before ending [infinite]

-d SEC, --delay=SEC delay between iterations [1 second]

-p PID, --pid=PID processes/threads to monitor [all]

-u USER, --user=USER users to monitor [all]

-P, --processes only show processes, not all threads

-a, --accumulated show accumulated I/O instead of bandwidth

-k, --kilobytes use kilobytes instead of a human friendly unit

-t, --time add a timestamp on each line (implies --batch)

-q, --quiet suppress some lines of header (implies --batch)