The tmp directory, short for “temporary” directory, is a system directory used by operating systems and applications to store temporary files and data during their operation. It serves as a temporary storage location for various processes, allowing them to create, manipulate, and delete temporary files as needed.

What actions are needed when the /tmp directory is 100% full?

When the tmp folder is 100% full, we need to remove the files and folder from the /tmp folder to free up some space.
There are two things to remember when managing the Linux /tmp directory.

• Firstly, you must know how to determine which files can be removed from the /tmp directory because randomly deleting files can disrupt user activity.
• Secondly, you need a way to make an automated process of cleaning up the directory. Because it is impossible to find and manually delete temporary files at regular intervals. With these two points in mind, the best solution is to periodically use crontab to remove the files from the tmp directory.

Shared servers

On shared servers, the /tmp directory is shared among all customers on the server.

When the /tmp directory becomes full, some programs stop working. For example, it is no longer be possible to upload a file to a site since there is no room in the /tmp folder to store the temporary file while it’s uploading.

Creating your personal /tmp directory

To maintain control of the temporary storage for files and add security for things such as sessions, you can configure the software to use any directory you want for temporary storage. Making this directory within your own user space (outside the web-accessible directory) is often desirable. For example, create a /tmp directory in the following location. Make sure to change username to your Shell user.

/home/username/tmp

Here you can control the /tmp directory while your files are protected from view by others on the server. You would control this directory based on the programming language your site is using. For example, if your site is using PHP, view the following link:

• PHP upload_tmp_dir

Purpose:

The temporary directory is designed to store files that are only needed temporarily and can be safely deleted once they are no longer required. These temporary files may include cache files, session data, log files, and intermediate results of various operations.

Location:

The temporary directory is typically located in the root directory of the filesystem on Unix-like operating systems, such as Linux and macOS. The exact location may vary depending on the specific operating system and filesystem configuration. Common locations include “/tmp” and “/var/tmp”.

Permissions:

The temporary directory is usually writable by all users, allowing processes to create temporary files regardless of the user’s privileges. However, strict permissions may be enforced to prevent unauthorized access or misuse of the temporary directory.

Cleanup:

The contents of the temporary directory are often cleared periodically to free up disk space and prevent it from becoming cluttered with unnecessary files. Many operating systems and applications include built-in mechanisms for automatically cleaning up temporary files based on predefined criteria, such as file age or disk usage.

Usage:

Various system processes, applications, and programming languages utilize the temporary directory to store temporary data during their execution. For example, web servers may use the tmp directory to store uploaded files temporarily before processing them, while software installers may extract temporary files during the installation process.

Security Considerations in tmp directory:

Since the tmp directory is accessible to all users, it is important to be cautious when storing sensitive or confidential information in temporary files. Developers should avoid storing sensitive data in plain text and ensure that temporary files are properly secured and deleted after use to prevent unauthorized access or data leaks.

Overall, the temporary directory plays a crucial role in the efficient operation of operating systems and applications by providing a convenient and temporary storage location for transient data and files. It helps maintain system cleanliness, disk space management, and system stability by managing temporary files effectively.