iotop (1) - Linux Manuals

iotop: simple top-like I/O monitor

NAME

iotop - simple top-like I/O monitor

SYNOPSIS

iotop [OPTIONS]

DESCRIPTION

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 and CONFIG_TASK_IO_ACCOUNTING options need to be enabled in your Linux kernel build configuration, these options depend on CONFIG_TASKSTATS.

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.

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.

OPTIONS

--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.

-q

column names are only printed on the first iteration,

-qq

column names are never printed,

-qqq

the I/O summary is never printed.

AUTHOR

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.