iotop

IOTOP(8) System Manager's Manual IOTOP(8)

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 and since Linux kernel 5.14, the kernel.task_delayacct sysctl enabled.

   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  un‐
   derlying  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 re‐
   ordering 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's 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.

   --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.