IOTOP(8)IOTOP(8)NAMEiotop - simple top-like I/O monitor
SYNOPSISiotop [OPTIONS]
DESCRIPTIONiotop 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 requires root or the NET_ADMIN capability.
iotop displays columns for the I/O bandwidth read and written by each
process/thread during the sampling period. It also displays the per‐
centage 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 --pro‐
cesses 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 tog‐
gled 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 choos‐
ing 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.
NOTES
The Linux kernel interfaces that iotop relies on require root privi‐
leges or the NET_ADMIN capability. This change occurred because a secu‐
rity issue (CVE-2011-2494) was found that allows leakage of sensitive
data across user boundaries. If you require the ability to run iotop as
a non-root user, please configure sudo to allow you to run iotop as
root.
SEE ALSOionice(1), top(1), vmstat(1)AUTHORiotop was written by Guillaume Chazarain.
This manual page was started by Paul Wise for the Debian project and is
placed in the public domain.
April 2009 IOTOP(8)
