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Checking system space

4. Checking System Space:​

Checking system space refers to monitoring and analyzing the disk space utilization on a Linux system. This is crucial for system maintenance, ensuring that there's enough space for applications and preventing disk space-related issues. Below, I'll explain how to check system space in detail using several commands and provide sample outputs.

  1. df (Disk Free):

    • df command displays information about disk space usage for mounted filesystems.
    df -h
    • The -h option makes the output human-readable (e.g., in gigabytes or megabytes). Sample output might look like this:
    Filesystem      Size  Used Avail Use% Mounted on
    /dev/sda1        50G   20G   28G  42% /
    /dev/sdb1       100G   80G   15G  85% /mnt/data
    • The columns represent the filesystem, total size, used space, available space, percentage used, and mount point.

  2. du (Disk Usage):

    • du calculates the disk usage of files and directories.
    du -sh /path/to/directory
    • The -s option gives a summary total, and the -h option makes the output human-readable. For example:
    2.4G    /path/to/directory
    • This command shows the total size of the specified directory and its subdirectories.

  3. ncdu (NCurses Disk Usage):

    • ncdu provides an interactive and more detailed view of disk usage.
    sudo apt install ncdu  # Install if not already installed
    ncdu /path/to/directory
    • After running the command, you'll get an interactive interface that allows you to navigate through directories, view sizes, and delete files if necessary.

  4. ls (List Files):

    • ls can help you identify large files in a directory.
    ls -lhS /path/to/directory | head -n 10
    • This command lists the largest files in a directory, sorted by size, with the largest files at the top.

  5. System Monitoring Tools:

    • Tools like top, htop, and iotop provide real-time information about system resource usage, including CPU, memory, and disk activity. They can help identify processes or activities that are consuming disk space.
    top
    • top displays a dynamic view of system resource usage, including disk activity.