iotop watches I/O usage information output by the Linux kernel
(requires 2.6.20 or later) and displays a table of current I/O usage
by processes or threads on the system. At least the
CONFIG_TASK_DELAY_ACCT, CONFIG_TASK_IO_ACCOUNTING, CONFIG_TASKSTATS
and CONFIG_VM_EVENT_COUNTERS options need to be enabled in your Linux
kernel build configuration.
iotop displays columns for the I/O bandwidth read and written by each
process/thread during the sampling period. It also displays the
percentage of time the thread/process spent while swapping in and
while waiting on I/O. For each process, its I/O priority
(class/level) is shown.
In addition, the total I/O bandwidth read and written during the
sampling period is displayed at the top of the interface. Total DISKREAD and Total DISK WRITE values represent total read and write
bandwidth between processes and kernel threads on the one side and
kernel block device subsystem on the other. While Current DISK READ
and Current DISK WRITE values represent corresponding bandwidths for
current disk I/O between kernel block device subsystem and underlying
hardware (HDD, SSD, etc.). Thus Total and Current values may not be
equal at any given moment of time due to data caching and I/O
operations reordering that take place inside Linux kernel.
Use the left and right arrows to change the sorting, r to reverse the
sorting order, o to toggle the --only option, p to toggle the
--processes option, a to toggle the --accumulated option, q to quit
or i to change the priority of a thread or a process' thread(s). Any
other key will force a refresh.
Show the version number and exit
Show usage information and exit
Only show processes or threads actually doing I/O, instead of
showing all processes or threads. This can be dynamically
toggled by pressing o.
Turn on non-interactive mode. Useful for logging I/O usage
-n NUM, --iter=NUM
Set the number of iterations before quitting (never quit by
default). This is most useful in non-interactive mode.
-d SEC, --delay=SEC
Set the delay between iterations in seconds (1 second by
default). Accepts non-integer values such as 1.1 seconds.
-p PID, --pid=PID
A list of processes/threads to monitor (all by default).
-u USER, --user=USER
A list of users to monitor (all by default)
Only show processes. Normally iotop shows all threads.
Show accumulated I/O instead of bandwidth. In this mode, iotop
shows the amount of I/O processes have done since iotop
Use kilobytes instead of a human friendly unit. This mode is
useful when scripting the batch mode of iotop. Instead of
choosing the most appropriate unit iotop will display all
sizes in kilobytes.
Add a timestamp on each line (implies --batch). Each line will
be prefixed by the current time.
suppress some lines of header (implies --batch). This option
can be specified up to three times to remove header lines.
Suppress the keyboard shortcuts help display.
-q column names are only printed on the first iteration,
-qq column names are never printed,
-qqq the I/O summary is never printed.
This page is part of the iotop (a simple top-like I/O monitor)
project. Information about the project can be found at
⟨http://guichaz.free.fr/iotop/⟩. If you have a bug report for this
manual page, send it to email@example.com. This page was obtained
from the project's upstream Git repository
⟨http://repo.or.cz/w/iotop.git⟩ on 2017-03-13. If you discover any
rendering problems in this HTML version of the page, or you believe
there is a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
April 2009 IOTOP(8)