Provided by: iotop_0.6-1_i386 bug

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_COUNTERS  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 Actual DISK READ  and
       Actual  DISK WRITE values represent corresponding bandwidths for actual
       disk I/O between kernel block device subsystem and underlying  hardware
       (HDD, SSD, etc.).  Thus Total and Actual 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 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.

SEE ALSO

       ionice(1), top(1), vmstat(1), atop(1), htop(1)

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)