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If you manage a Linux server and notice slow performance, high disk usage, or unexplained I/O activity, iotop is the first tool you should reach for. It works like the familiar top command but focuses entirely on disk read and write activity, showing you exactly which process is responsible, in real time.
This guide covers everything you need to get iotop running on your system: installation commands for every major Linux distribution, including Ubuntu, Fedora, Debian, CentOS, Linux Mint, and Arch, followed by usage examples, a full flag reference, and fixes for the most common errors like iotop command not found.
Whether you’re installing iotop for the first time or troubleshooting why it isn’t working, you’ll find the exact command for your distro below.
What Is iotop?
iotop is a Linux command-line tool that monitors disk I/O (input/output) usage in real time, broken down by process. It works similarly to top, which monitors CPU and memory, but focuses specifically on which processes are reading from and writing to disk.
iotop is essential for diagnosing:
- Processes causing unexpectedly high disk usage on a server
- Applications performing excessive read/write operations
- Slow server performance caused by disk I/O bottlenecks
- Runaway processes writing large amounts of data to disk
Install iotop on all Linux Distributions
Select your Linux distribution below. iotop is available in the default repositories of all major distros, so no third-party sources are needed.
Ubuntu Ubuntu 20.04 / 22.04 / 24.04
# Update package list sudo apt update # Install iotop sudo apt install iotop -y
Debian Debian 10 / 11 / 12
# Update and install
sudo apt update
sudo apt install iotop -y
Linux Mint Linux Mint 20 / 21
# Same as Ubuntu (apt-based)
sudo apt update
sudo apt install iotop -y
Fedora Fedora 38 / 39 / 40 / 41
# Install using DNF sudo dnf install iotop -y # Or the maintained fork sudo dnf install iotop-c -y
CentOS / RHEL 7 CentOS 7 · RHEL 7
# Install using YUM
sudo yum install iotop -y
CentOS / RHEL 8+ CentOS 8+ · RHEL 8+ · Rocky · AlmaLinux
# Install using DNF
sudo dnf install iotop -y
Arch Linux Arch Linux · Manjaro
# Install using pacman
sudo pacman -S iotop
openSUSE openSUSE Leap / Tumbleweed
# Install using zypper
sudo zypper install iotop
Verify installation
After installing, confirm iotop is available by checking its version:
Bash
iotop --version iotop 0.6
If you get
iotop: command not found after installing, see the troubleshooting section below. The most common cause is that the install completed but the shell needs to be refreshed, or iotop was installed as iotop-c on newer Fedora systems.Install iotop on Fedora (Full Guide)
Fedora uses the DNF package manager. iotop is available in Fedora’s default repositories; no extra configuration or EPEL setup needed.
1. Open a terminal and ensure you have sudo privileges or are logged in as root.
2. Install iotop using DNF:
3. Run iotop to confirm it works:
Is iotop pre-installed on Fedora?
No. iotop is not included in Fedora’s default installation. It must be installed manually using DNF. This applies to all Fedora versions, including Fedora 38, 39, 40, and 41, as well as both Fedora Workstation and Fedora Server editions.
Install iotop on Fedora 40 / 41 specifically
On Fedora 40 and later, you can install either the original iotop or the maintained C rewrite iotop-c. Both are in the default Fedora repositories:
What Is iotop-c? Original vs Maintained Fork
If you’ve searched for iotop on Fedora and seen both iotop and iotop-c as package options, here’s the difference:
| Feature | iotop (original) | iotop-c (fork) |
|---|---|---|
| Language | Python | C |
| Maintenance | No longer active | Actively maintained |
| Performance | Slower (Python overhead) | Faster, lower resource use |
| Commands | iotop |
iotop-c or iotop (aliased) |
| Fedora package | dnf install iotop |
dnf install iotop-c |
| Ubuntu/Debian | apt install iotop |
Not in default apt repos |
| Recommended? | Still works | Yes, on Fedora 36+ |
For Ubuntu and Debian users: stick with apt install iotop. For Fedora users: sudo dnf install iotop-c is the better long-term choice, but either works.
How to Use iotop
Once installed, iotop is run from the terminal. It requires root privileges to access per-process I/O data from the kernel.
Basic usage
Common usage examples
Interactive keyboard shortcuts
While iotop is running, use these keyboard shortcuts to control the display:
| Key | Action |
|---|---|
| o | Toggle — show only processes with active I/O |
| a | Toggle — switch between current and accumulated I/O |
| r | Reverse sort order |
| ← → | Change the column being sorted |
| i | Change I/O priority of a process |
| u | Filter by user |
| p | Filter by process name |
| q | Quit iotop |
Troubleshooting: Fix Common iotop Errors
iotop: command not found
Cause: iotop is not installed, or was installed as
iotop-c on Fedora.Fix Ubuntu/Debian:
sudo apt install iotop -y
Fix Fedora:
# Try iotop-c if iotop is not found sudo dnf install iotop-c -y # Then run with: sudo iotop-c
Fix if installed but still not found: Close and reopen your terminal, or run hash -r to refresh the shell’s command cache.
iotop: Permission denied / must be run as root
Cause: iotop was run without root privileges. It needs access to kernel I/O statistics, which requires root access.
Fix: Always run iotop with sudo:
sudo iotop
Couldn’t run iotop — Linux kernel too old
Cause: iotop requires Linux kernel 2.6.20 or later (with the CONFIG_TASK_IO_ACCOUNTING option enabled). This is present in all modern kernels but may be missing on older or custom-built kernels.
Fix: Check your kernel version with uname -r. If it is below 2.6.20 or is a custom kernel, update your kernel or enable the task I/O accounting option during compilation.
No processes appear / blank output
Cause: By default, iotop shows all processes, including idle ones. If disk activity is very low, the list may appear empty or show zeros.
Fix: Use the -o flag to show only processes actively performing I/O:
sudo iotop -o
sudo: iotop: command not found (even after installing)
Cause: sudo uses a restricted PATH that may not include the directory where iotop was installed (commonly /usr/sbin).
Fix: Use the full path:
# Find where iotop is installed which iotop # Run with full path sudo /usr/sbin/iotop
Comparison iotop vs atop vs btop — Which Should You Use?
iotop isn’t the only Linux monitoring tool. Here’s how it compares to other popular options so you can choose the right tool for your situation.
| Tool | Primary focus | Disk I/O | CPU / RAM | Network | Per-process | Best for |
|---|---|---|---|---|---|---|
| iotop | Disk I/O only | ✓ Detailed | ✗ | ✗ | ✓ | Diagnosing I/O spikes fast |
| atop | All resources over time | ✓ | ✓ | ✓ | ✓ | Historical analysis & logging |
| btop | All resources (visual) | Basic | ✓ | ✓ | ✓ | General monitoring with graphs |
| top / htop | CPU & memory | ✗ | ✓ Detailed | ✗ | ✓ | CPU/memory troubleshooting |
| iostat | Block device I/O | ✓ | Basic | ✗ | By device only | Disk throughput per device |
Rule of thumb: Use iotop when you need to find which specific process is hammering your disk. Use atop when you need historical logs of what happened. Use btop for a general-purpose visual dashboard.
Related: How to Monitor System Resource Usage Using atop
FAQ’s
- How do I install iotop on Fedora using DNF?
Run sudo dnf install iotop -y in your terminal. iotop is available in Fedora’s default repositories; no EPEL or third-party repo is needed. On Fedora 36 and later, you can also install the maintained fork with sudo dnf install iotop-c -y. - Is iotop pre-installed on Fedora?
No. iotop is not included in Fedora’s default installation. It must be installed manually with sudo dnf install iotop. This applies to both Fedora Workstation and Fedora Server across all recent versions, including Fedora 38, 39, 40, and 41. - How do I install iotop on Ubuntu?
Run sudo apt update && sudo apt install iotop -y. iotop is in Ubuntu’s default universe repository and works on Ubuntu 20.04, 22.04, and 24.04 LTS without any additional setup. - How do I fix “iotop command not found”?
First install iotop for your distro: sudo apt install iotop on Ubuntu/Debian, or sudo dnf install iotop on Fedora. If it’s installed but still not found, try running it with the full path (sudo /usr/sbin/iotop), or refresh your shell with hash -r. On Fedora, try sudo iotop-c if iotop isn’t found after installing iotop-c. - What is the difference between iotop and iotop-c?
iotop is the original Python-based tool, which is no longer actively maintained. iotop-c is a rewrite in C that is actively maintained, faster, and uses fewer resources. On Fedora, both are available via DNF. On Ubuntu and Debian, only the original iotop is in the default repositories. - How do I use iotop to show only active processes?
Run sudo iotop -o. The -o flag filters the display to show only processes that are currently performing disk read or write operations, making it much easier to identify which process is responsible for I/O activity. - How do I install iotop on Debian?
Run sudo apt update && sudo apt install iotop -y. iotop is available in Debian’s default repositories for Debian 10 (Buster), Debian 11 (Bullseye), and Debian 12 (Bookworm). No additional configuration is needed. - Can I install iotop on CentOS 7 using yum?
Yes. On CentOS 7 and RHEL 7, run sudo yum install iotop -y. On CentOS 8, CentOS Stream, RHEL 8+, Rocky Linux, and AlmaLinux, use DNF instead: sudo dnf install iotop -y.
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