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 (re‐
13 quires 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_DE‐
15 LAY_ACCT, CONFIG_TASK_IO_ACCOUNTING, CONFIG_TASKSTATS and CON‐
16 FIG_VM_EVENT_COUNTERS options need to be enabled in your Linux kernel
17 build configuration and since Linux kernel 5.14, the kernel.task_delay‐
18 acct sysctl enabled.
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.
25 In addition, the total I/O bandwidth read and written during the sam‐
27 pling period is displayed at the top of the interface. Total DISK READ
28 and Total DISK WRITE values represent total read and write bandwidth
29 between processes and kernel threads on the one side and kernel block
30 device subsystem on the other. While Current DISK READ and Current DISK
31 WRITE values represent corresponding bandwidths for current disk I/O
32 between kernel block device subsystem and underlying hardware (HDD,
33 SSD, etc.). Thus Total and Current values may not be equal at any
34 given moment of time due to data caching and I/O operations reordering
35 that take place inside Linux kernel.
36 Use the left and right arrows to change the sorting, r to reverse the
38 sorting order, o to toggle the --only option, p to toggle the --pro‐
39 cesses option, a to toggle the --accumulated option, q to quit or i to
40 change the priority of a thread or a process's thread(s). Any other key
41 will force a refresh.
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44 --version
45 Show the version number and exit
46 -h, --help
48 Show usage information and exit
49 -o, --only
51 Only show processes or threads actually doing I/O, instead of
52 showing all processes or threads. This can be dynamically tog‐
53 gled by pressing o.
54 -b, --batch
56 Turn on non-interactive mode. Useful for logging I/O usage over
57 time.
58 -n NUM, --iter=NUM
60 Set the number of iterations before quitting (never quit by de‐
61 fault). This is most useful in non-interactive mode.
62 -d SEC, --delay=SEC
64 Set the delay between iterations in seconds (1 second by de‐
65 fault). Accepts non-integer values such as 1.1 seconds.
66 -p PID, --pid=PID
68 A list of processes/threads to monitor (all by default).
69 -u USER, --user=USER
71 A list of users to monitor (all by default)
72 -P, --processes
74 Only show processes. Normally iotop shows all threads.
75 -a, --accumulated
77 Show accumulated I/O instead of bandwidth. In this mode, iotop
78 shows the amount of I/O processes have done since iotop started.
79 -k, --kilobytes
81 Use kilobytes instead of a human friendly unit. This mode is
82 useful when scripting the batch mode of iotop. Instead of choos‐
83 ing the most appropriate unit iotop will display all sizes in
84 kilobytes.
85 -t, --time
87 Add a timestamp on each line (implies --batch). Each line will
88 be prefixed by the current time.
89 -q, --quiet
91 suppress some lines of header (implies --batch). This option can
92 be specified up to three times to remove header lines.
93 --no-help
95 Suppress the keyboard shortcuts help display.
96 -q column names are only printed on the first iteration,
97 -qq column names are never printed,
98 -qqq the I/O summary is never printed.
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101 ionice(1), top(1), vmstat(1), atop(1), htop(1)
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104 iotop was written by Guillaume Chazarain.
105 This manual page was started by Paul Wise for the Debian project and is
107 placed in the public domain.
108 April 2009 IOTOP(8)