How to Check Disk Usage and Free Space in Ubuntu

Monitoring disk usage and ensuring sufficient free space is crucial for maintaining the performance and stability of your Ubuntu system. Whether you're running out of space or want to analyze how your disk is being used, Ubuntu provides various tools and commands to help you manage disk space effectively. This guide will walk you through both terminal-based and GUI methods for checking disk usage and free space in Ubuntu.

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1. Using the Terminal to Check Disk Usage

The terminal is a powerful tool for quickly accessing disk usage information. Below are some commonly used commands:

Command 1: df

The df (disk filesystem) command provides an overview of disk space usage:

• To display disk usage in human-readable format:

  df -h

  Output includes:

  • Filesystem name

  • Total size

  • Used space

  • Available space

  • Usage percentage

  • Mounted location

Command 2: du

The du (disk usage) command gives detailed information about directory and file sizes:

• To check the size of the current directory:

  du -sh

• To display sizes of all files and subdirectories:

  du -h

• To sort output by size and find the largest directories:

  du -ah | sort -rh | head -n 10

Command 3: ls

The ls command can also help analyze file sizes:

• To list files and their sizes in human-readable format:

  ls -lh

• To sort files by size:

  ls -lSh

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2. Using GUI Tools to Check Disk Usage

If you prefer graphical interfaces, Ubuntu offers built-in and third-party tools:

Disk Usage Analyzer (Baobab)

• Description: A graphical tool that visually displays disk usage.

• How to Install:

  sudo apt install baobab

• How to Use:

  1. Launch it by searching for "Disk Usage Analyzer" in the Applications menu.

  2. Select a specific folder or entire filesystem to analyze.

  3. View disk usage represented as charts and graphs.

File Manager (Nautilus)

• Open the file manager and right-click on any folder or drive.

• Select "Properties" to view size, free space, and used space.

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3. Identifying Large Files and Directories

To free up disk space, you need to locate large files and directories. Use the following methods:

Using find Command

• To locate files larger than 100MB:

  find /path/to/directory -type f -size +100M

• To delete large files (use caution):

  find /path/to/directory -type f -size +100M -delete

Using ncdu

• Description: A text-based disk usage analyzer.

• How to Install:

  sudo apt install ncdu

• How to Use:

  ncdu

  Navigate directories and view their sizes interactively.

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4. Checking Mounted Drives and Partitions

Command: lsblk

• Use lsblk to display information about block devices, including mounted drives:

  lsblk

  Output includes partition names, sizes, and mount points.

Command: mount

• To see all mounted filesystems:

  mount | column -t

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5. Cleaning Up Disk Space

If you’re running low on space, try these commands to free up space:

• Remove Unused Packages:

  sudo apt autoremove

• Clean Cached Package Files:

  sudo apt clean

• Purge Old Kernels:

  sudo apt --purge autoremove

• Delete Temporary Files:

  sudo rm -rf /tmp/*

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6. Scheduling Disk Usage Monitoring

Automate disk usage checks using cron jobs:

1. Open the cron editor:

   crontab -e

2. Add a job to monitor disk usage daily:

   0 9 * * * df -h > ~/disk_usage_report.txt

3. Check the report in your home directory.

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Conclusion

Monitoring disk usage and free space in Ubuntu is essential for system maintenance. Whether you prefer terminal commands like df and du or graphical tools like Disk Usage Analyzer, Ubuntu provides a variety of methods to analyze and manage your storage efficiently. Regularly check your disk usage and clean up unnecessary files to keep your system running smoothly.