What is a file system?
A file system represents a collection of files stored in a specific way on a system. There are many ways to keep files and, as you probably already know, there are also many file systems types. Each type will describe a uniform method meant to store files on a storage medium. Think about this as a hard disk partition. If this storage will be different it would be very difficult for you to share these files with other people.
All directories and files are kept into a high tree rooted at ‘/’. This is like a tree because if the file system would be drawn it will be like a tree upside down. These can be spread out over more devices and you can attach the file system using mount(8).
On Debian system the folders are called directories. There is no drive concept (such as “A:”). You have only one file system where all you need is included. Compared to windows you will find this to be a great advantage.
Here are some basic details regarding the file system on Debian operating system:
- You will have to use case sensitive mode for all files, ‘FILE’ and ‘file’ are completely different documents
- When you refer to root directory it means you talk about the root of the file system: ‘/’. This is different from the home directory for the root user: ‘/root’.
- You can use for your file and directory names any symbol or letter. The only character you cannot use is ‘/’, this being a representation for the root directory
- The root directory filename (/) cannot be renamed
- All directories and files are designated by a path or an absolute filename, which will show the full sequence which needs to be passed in order to reach to that specific file
- Several branches can be found in the root directory: ‘/etc/’ or ‘/usr/’. These have also other branches, such as ‘/etc/init.d/’ or ‘/usr/local/’.
- There is no specific path having a correspondent to a physical device
- You can find more information about this in the file system hierarchy standard
Here you can find some key directories and their specific usage:
- 1. / – this is the root directory
- 2. /etc/ – this is the place for the configuration files
- 3. /var/log/ – find system log files here
- 4. /home/ – home directories
Next, each file has its own permissions. Read permission will allow the user to read the content of a file. Write permission will allow the user to change the content of that file. Execute permission will allow the user to execute that file as a command. Using the command ‘ls(1)’ you will be able to see the permission information for the files and directories and when it is invoked with “-1” it will display more information such as file type, number of hard links to that file, owner username, its group or size.
We hope this starter material for Debian file system will help you get a basic overview meant to help you in the future.