1IOTOP(8) System Manager's Manual IOTOP(8)
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6 iotop - simple top-like I/O monitor
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9 iotop [OPTIONS]
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12 iotop watches I/O usage information output by the Linux kernel
13 (requires 2.6.20 or later) and displays a table of current I/O usage by
14 processes or threads on the system. At least the CONFIG_TASK_DELAY_ACCT
15 and CONFIG_TASK_IO_ACCOUNTING options need to be enabled in your Linux
16 kernel build configuration, these options depend on CONFIG_TASKSTATS.
17 iotop requires root or the NET_ADMIN capability.
19 iotop displays columns for the I/O bandwidth read and written by each
21 process/thread during the sampling period. It also displays the per‐
22 centage of time the thread/process spent while swapping in and while
23 waiting on I/O. For each process, its I/O priority (class/level) is
24 shown. In addition, the total I/O bandwidth read and written during
25 the sampling period is displayed at the top of the interface.
26 Use the left and right arrows to change the sorting, r to reverse the
28 sorting order, o to toggle the --only option, p to toggle the --pro‐
29 cesses option, a to toggle the --accumulated option, q to quit or i to
30 change the priority of a thread or a process' thread(s). Any other key
31 will force a refresh.
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34 --version
35 Show the version number and exit
36 -h, --help
38 Show usage information and exit
39 -o, --only
41 Only show processes or threads actually doing I/O, instead of
42 showing all processes or threads. This can be dynamically tog‐
43 gled by pressing o.
44 -b, --batch
46 Turn on non-interactive mode. Useful for logging I/O usage over
47 time.
48 -n NUM, --iter=NUM
50 Set the number of iterations before quitting (never quit by
51 default). This is most useful in non-interactive mode.
52 -d SEC, --delay=SEC
54 Set the delay between iterations in seconds (1 second by
55 default). Accepts non-integer values such as 1.1 seconds.
56 -p PID, --pid=PID
58 A list of processes/threads to monitor (all by default).
59 -u USER, --user=USER
61 A list of users to monitor (all by default)
62 -P, --processes
64 Only show processes. Normally iotop shows all threads.
65 -a, --accumulated
67 Show accumulated I/O instead of bandwidth. In this mode, iotop
68 shows the amount of I/O processes have done since iotop started.
69 -k, --kilobytes
71 Use kilobytes instead of a human friendly unit. This mode is
72 useful when scripting the batch mode of iotop. Instead of choos‐
73 ing the most appropriate unit iotop will display all sizes in
74 kilobytes.
75 -t, --time
77 Add a timestamp on each line (implies --batch). Each line will
78 be prefixed by the current time.
79 -q, --quiet
81 suppress some lines of header (implies --batch). This option can
82 be specified up to three times to remove header lines.
83 -q column names are only printed on the first iteration,
84 -qq column names are never printed,
85 -qqq the I/O summary is never printed.
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88 The Linux kernel interfaces that iotop relies on require root privi‐
89 leges or the NET_ADMIN capability. This change occurred because a secu‐
90 rity issue (CVE-2011-2494) was found that allows leakage of sensitive
91 data across user boundaries. If you require the ability to run iotop as
92 a non-root user, please configure sudo to allow you to run iotop as
93 root.
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96 ionice(1), top(1), vmstat(1)
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99 iotop was written by Guillaume Chazarain.
100 This manual page was started by Paul Wise for the Debian project and is
102 placed in the public domain.
103 April 2009 IOTOP(8)