iotop(8) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | SEE ALSO | AUTHOR | COLOPHON

IOTOP(8)                 System Manager's Manual                IOTOP(8)

NAME         top

       iotop - simple top-like I/O monitor

SYNOPSIS         top

       iotop [OPTIONS]

DESCRIPTION         top

       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
       DISK READ 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's
       thread(s). Any other key will force a refresh.

OPTIONS         top

       --version
              Show the version number and exit

       -h, --help
              Show usage information and exit

       -o, --only
              Only show processes or threads actually doing I/O, instead
              of showing all processes or threads. This can be
              dynamically toggled by pressing o.

       -b, --batch
              Turn on non-interactive mode.  Useful for logging I/O
              usage over time.

       -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)

       -P, --processes
              Only show processes. Normally iotop shows all threads.

       -a, --accumulated
              Show accumulated I/O instead of bandwidth. In this mode,
              iotop shows the amount of I/O processes have done since
              iotop started.

       -k, --kilobytes
              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.

       -t, --time
              Add a timestamp on each line (implies --batch). Each line
              will be prefixed by the current time.

       -q, --quiet
              suppress some lines of header (implies --batch). This
              option can be specified up to three times to remove header
              lines.

       --no-help
              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.

SEE ALSO         top

       ionice(1), top(1), vmstat(1), atop(1), htop(1)

AUTHOR         top

       iotop was written by Guillaume Chazarain.

       This manual page was started by Paul Wise for the Debian project
       and is placed in the public domain.

COLOPHON         top

       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 guichaz@gmail.com.  This page was
       obtained from the project's upstream Git repository
       ⟨git://repo.or.cz/iotop.git⟩ on 2021-08-27.  (At that time, the
       date of the most recent commit that was found in the repository
       was 2021-05-13.)  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
       man-pages@man7.org

                               April 2009                       IOTOP(8)