File System
Set default file permissions on Linux with umask
Learn how to use umask to set the default file permissions in Linux. We look at examples, including how and where to implement them.
How to monitor disk activity (I/O) on Linux
Got a busy Linux systems and wondering what the culprit is? Learn how to monitor them and focus on disk activity with tools like iotop, sar, vmstat, or iostat.
How to see the file type on Linux
The file command is a powerful tool for Linux users. Learn how to see the file type of normal and special files on a Linux system.
How to see the size of a file
File systems on Linux store a lot more than just the data itself. Learn how to see the size of a file on Linux systems using the ls or stat command.
How to display directory contents sorted by modification time
Learn how to sort the output of the ls command and list a directory contents by its modification time. Here is which options to use.
How to find writable files
Use the find command to search for any files on Linux that are writable. To make this work, the -perm option of find can be used.
How to see the size of a directory
Disks will eventually fill up. Learn how to quickly see the size of a directory or folder on Linux systems using the du command.
How to see hidden files
Files starting with a dot are usually hidden on Linux. Learn how to see any hidden files on the command line or in the terminal using the ls command.
How to see files greater than a specific size
Learn how to see files smaller or bigger than a specific defined size on Linux, using the du command. Or use the find command to achieve a similar result.
How to find when the last modification happened in a directory
Linux filesystems typically store file modification timestamps. Learn how to find the last modification time of a file or subdirectory in a specified directory.
How to see inode usage
Linux file systems use inodes, unique references to link to a file or directory. Learn how to see inode usage on a Linux file system or mount point.
How to see used and free disk space
Learn how to see used and remaining disk space on Linux systems by gathering the statistics of file systems and mount points using the df command.
How to find symbolic links that point to a directory
Symbolic links may point to a directory or a file. Learn how to use the find command to discover symbolic links that refer to a directory.
How to compare two directories and find the differences
Learn how to compare two directories on a Linux systems and see their differences between both or what files they are having in common.
How to securely delete a file and its contents
Need to delete the contents of a sensitive file on Linux? Instead of just deleting it with rm, have a look at some other options for a more secure deletion.
How to see the creation date of a file
Linux may store the initial creation of a file. Learn how to use the stat command to find this initial creation time of a file, also known as its birth time.
Understanding the output of the stat command
Learn everything about the output that the stat command returns. Great for forensics, intrusion detection, and system administration.
How to find the biggest directories on disk
Find the biggest directories and files on disk by using the du command. The output can be sorted using numeric values to find the biggest entries.
How to change file permissions
Learn how to change the file permissions of files and directories on a Linux system. Follow the examples and make your system more secure.
Linux file permissions
Learn the basics of file permissions on Linux systems and filesystems such as ext4, XFS, and ZFS. Guided by examples and common Linux tools.
Introduction in Linux file permissions
Learn the basics of how a Linux system applies file permissions. We look at examples to demystify the permissions mean and learn to troubleshoot common issues.
How to find hard links or files that point to a specific file
Learn how to find hardlinks on a file system or which files they have in common. We will use the find command to get this information quickly available.
Linux file systems
All articles about the purpose of a file system and how it works. Learn how to become a specialist to further secure your system.
The purpose of the /etc/networks file
Also wondering what some files are used for on Linux systems? In this article we have a look at the /etc/networks file and show some configuration.
Linux system hardening: adding hidepid to /proc mount point
The pseudo-filesystem /proc contains a lot of useful information for the system administrator. With the hidepid option we can restrict what users can see.
Linux History: How Dot Files Became Hidden Files
Ever wondered why there are files on your Linux system, starting with a dot? The short answer: they are shortcuts. Here is the full story.
Using xattrs or Extended Attributes on Linux
Linux supports extended attributes (xattr) on most file systems. Learn how they work and allow security features like access control lists and more.
Securing mount points on Linux
Since data is stored on file systems, appropriate measures should be taken to protect it. Learn how to secure mount points on Linux.
Plus sign in ls output
When file access control lists, or ACLs are being used, the output of ls will change. Learn about the additional plus sign in its output.