Linux iotop Command with Practical Examples

Introduction

In this lab, you will learn how to use the iotop command in Linux to monitor and analyze disk I/O usage in real-time. iotop is a command-line tool that provides detailed information about the processes that are utilizing the most disk I/O, allowing you to identify performance bottlenecks and optimize system performance.

The lab covers the following steps: understanding the purpose and functionality of iotop, installing and configuring iotop on Ubuntu 22.04, and analyzing disk I/O usage with iotop. By the end of this lab, you will have a better understanding of how to use iotop to monitor and manage disk I/O on your Linux system.

Linux Commands Cheat Sheet

Skills Graph

%%%%{init: {'theme':'neutral'}}%%%% flowchart RL linux(("Linux")) -.-> linux/PackagesandSoftwaresGroup(["Packages and Softwares"]) linux(("Linux")) -.-> linux/SystemInformationandMonitoringGroup(["System Information and Monitoring"]) linux(("Linux")) -.-> linux/UserandGroupManagementGroup(["User and Group Management"]) linux/SystemInformationandMonitoringGroup -.-> linux/du("File Space Estimating") linux/SystemInformationandMonitoringGroup -.-> linux/ps("Process Displaying") linux/SystemInformationandMonitoringGroup -.-> linux/top("Task Displaying") linux/UserandGroupManagementGroup -.-> linux/sudo("Privilege Granting") linux/PackagesandSoftwaresGroup -.-> linux/apt("Package Handling") subgraph Lab Skills linux/du -.-> lab-422740{{"Linux iotop Command with Practical Examples"}} linux/ps -.-> lab-422740{{"Linux iotop Command with Practical Examples"}} linux/top -.-> lab-422740{{"Linux iotop Command with Practical Examples"}} linux/sudo -.-> lab-422740{{"Linux iotop Command with Practical Examples"}} linux/apt -.-> lab-422740{{"Linux iotop Command with Practical Examples"}} end

Understand the Purpose and Functionality of iotop

In this step, you will learn about the purpose and functionality of the iotop command in Linux. iotop is a command-line tool that monitors disk I/O usage in real-time, providing detailed information about the processes that are utilizing the most disk I/O.

To understand the purpose of iotop, let's first explore the importance of monitoring disk I/O in a system. Disk I/O (Input/Output) refers to the transfer of data between the system's memory and storage devices, such as hard drives or solid-state drives (SSDs). Monitoring disk I/O is crucial because it can help identify performance bottlenecks, detect resource-intensive processes, and optimize system performance.

iotop provides the following key functionalities:

Real-time Monitoring: iotop displays the current disk I/O usage in real-time, allowing you to observe the system's performance and identify any issues as they occur.
Process-level Details: iotop provides detailed information about the processes that are consuming the most disk I/O, including the process ID, user, read and write rates, and the total disk I/O usage.
Sorting and Filtering: iotop allows you to sort the output by various criteria, such as read or write rates, and filter the results to focus on specific processes or users.
Resource Utilization Insights: By understanding the disk I/O usage patterns, you can identify resource-intensive processes, optimize disk-related operations, and improve overall system performance.

Let's move on to the next step, where you will learn how to install and configure iotop on your Ubuntu 22.04 system.

Install and Configure iotop on Ubuntu 22.04

In this step, you will learn how to install and configure the iotop command on your Ubuntu 22.04 system.

First, let's update the package index and install the iotop package:

sudo apt-get update
sudo apt-get install -y iotop

Example output:

Hit:1 http://archive.ubuntu.com/ubuntu jammy InRelease
Get:2 http://security.ubuntu.com/ubuntu jammy-security InRelease [110 kB]
...
Fetching 172 kB in 0s (0 B/s)
Extracting templates from packages: 100%
Reading package lists... Done
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
The following NEW packages will be installed:
  iotop
0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
Need to get 44.5 kB of archives.
After this operation, 141 kB of additional disk space will be used.
Get:1 http://archive.ubuntu.com/ubuntu jammy/universe amd64 iotop amd64 1.22-2 [44.5 kB]
Fetching packages...
Selecting previously unselected package iotop.
(Reading database ... 25105 files and directories currently installed.)
Preparing to unpack .../iotop_1.22-2_amd64.deb ...
Unpacking iotop (1.22-2) ...
Setting up iotop (1.22-2) ...
Processing triggers for man-db (2.10.2-1) ...

Now that iotop is installed, let's explore its configuration options. iotop doesn't require any specific configuration, but you can customize its behavior by using command-line options.

Some commonly used iotop options include:

-o: Only show processes actually doing I/O
-b: Print in a batch mode, without ncurses
-n NUM: Number of iterations before ending
-d DELAY: Delay between iterations, in seconds (default 3)

For example, to run iotop in batch mode and show only the processes actually doing I/O, you can use the following command:

sudo iotop -o -b

Example output:

Total DISK READ: 0.00 B/s | Total DISK WRITE: 0.00 B/s
  TID  PRIO  USER     DISK READ  DISK WRITE  SWAPIN     IO>    COMMAND
  1234 be/4 labex     0.00 B/s   0.00 B/s  0.00 %  0.00 % iotop
  5678 be/4 labex     0.00 B/s   0.00 B/s  0.00 %  0.00 % bash
  9012 be/4 labex     0.00 B/s   0.00 B/s  0.00 %  0.00 % sleep 60

This will run iotop in batch mode, displaying only the processes that are currently performing disk I/O.

Now that you have installed and configured iotop, let's move on to the next step, where you will learn how to analyze disk I/O usage with iotop.

Analyze Disk I/O Usage with iotop

In this step, you will learn how to use the iotop command to analyze disk I/O usage on your Ubuntu 22.04 system.

First, let's start the iotop command in interactive mode:

sudo iotop

This will display a real-time view of the disk I/O usage on your system. The output will show the following information:

TID: The process ID of the process using disk I/O.
PRIO: The I/O priority of the process.
USER: The user running the process.
DISK READ: The read rate of the process in bytes per second.
DISK WRITE: The write rate of the process in bytes per second.
SWAPIN: The percentage of time the process has spent waiting on swap.
IO>: The percentage of time the process has spent performing I/O.
COMMAND: The command line of the process.

You can use the following keys to interact with iotop:

Left/Right Arrow: Cycle through the available columns.
Up/Down Arrow: Scroll through the list of processes.
o: Toggle between showing all processes and only those actually performing I/O.
p: Toggle between showing current and cumulative I/O usage.
a: Toggle between showing I/O usage in bytes per second or in total bytes.
q: Quit the iotop command.

For example, to show only the processes actually performing I/O, press the 'o' key. To toggle between showing current and cumulative I/O usage, press the 'p' key.

Once you have identified the processes consuming the most disk I/O, you can take appropriate actions to optimize your system's performance, such as:

Identifying and addressing resource-intensive processes.
Optimizing disk-related operations, such as reducing unnecessary disk writes.
Monitoring and managing disk I/O-intensive applications or services.

Now that you have learned how to use iotop to analyze disk I/O usage, you have completed the Lab on the Linux iotop command.

Summary

In this lab, you first learned about the purpose and functionality of the iotop command in Linux. iotop is a powerful tool that provides real-time monitoring of disk I/O usage, allowing you to identify resource-intensive processes and optimize system performance. You then learned how to install and configure iotop on your Ubuntu 22.04 system, ensuring you have the necessary tools to analyze disk I/O usage.

Linux Commands Cheat Sheet