# IOTOP(8) - man - phpman

[IOTOP(8)](https://www.chedong.com/phpMan.php/man/IOTOP/8/markdown)                               System Manager's Manual                              [IOTOP(8)](https://www.chedong.com/phpMan.php/man/IOTOP/8/markdown)



## 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, CONFIG_TASK_IO_ACCOUNTING, CONFIG_TASKSTATS and CONFIG_VM_EVENT_COUN‐
       TERS 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' 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 --iter
              Set the number of iterations before quitting (never quit by default).   This  is  most
              useful in non-interactive mode.

### -d --delay
              Set  the delay between iterations in seconds (1 second by default).  Accepts non-inte‐
              ger values such as 1.1 seconds.

### -p --pid
              A list of processes/threads to monitor (all by default).

### -u --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 cur‐
              rent 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
       [**ionice**(1)](https://www.chedong.com/phpMan.php/man/ionice/1/markdown), [**top**(1)](https://www.chedong.com/phpMan.php/man/top/1/markdown), [**vmstat**(1)](https://www.chedong.com/phpMan.php/man/vmstat/1/markdown), [**atop**(1)](https://www.chedong.com/phpMan.php/man/atop/1/markdown), [**htop**(1)](https://www.chedong.com/phpMan.php/man/htop/1/markdown)

## 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.



                                             April 2009                                     [IOTOP(8)](https://www.chedong.com/phpMan.php/man/IOTOP/8/markdown)