What Is /var/cache

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Last updated: April 11, 2026

Quick Answer: /var/cache is a directory in Linux and Unix-like operating systems that stores temporary cache data for applications and system services. According to the Filesystem Hierarchy Standard (FHS), introduced in 1994, this directory is designed to hold application cache files that can be safely deleted without affecting system functionality, though doing so may temporarily impact performance. The cache data stored here helps applications run faster by avoiding repeated computations or downloads.

Key Facts

Created as part of the Filesystem Hierarchy Standard (FHS) Version 2.2, released in 2000, to provide a standard location for cache files
Cache data in /var/cache can be deleted safely without breaking system functionality, as it contains only temporary data that applications can regenerate
Linux systems typically allocate between 5-20% of available disk space to cache directories depending on system usage patterns and available storage
Major applications like apt (package manager), man (manual pages), and nginx (web server) use /var/cache to store frequently accessed data
Cleaning /var/cache can free up 100MB to several GB of disk space on average systems, with web servers and package managers often accounting for 50% of cached data

Overview

/var/cache is a standard directory found in Linux, BSD, and other Unix-like operating systems that serves as a centralized storage location for application cache files. Defined by the Filesystem Hierarchy Standard (FHS), which was first introduced in 1994 and formalized in version 2.2 in 2000, this directory contains temporary data that applications generate to improve performance. Unlike system files in /var or permanent user data, cache contents are expendable and can be safely removed without compromising system stability or functionality.

The purpose of /var/cache is to provide a consistent, standard location where developers can store cached data according to system conventions rather than using arbitrary temporary directories. This standardization allows system administrators to manage cache across multiple applications from a single location and helps prevent disk space issues. Cache files can include downloaded packages, compiled files, web server cached content, DNS resolver caches, and font caches—essentially any data that can be quickly regenerated if needed.

How It Works

The /var/cache directory operates on a simple principle: applications read and write temporary data that improves their performance without storing essential information. Here's how it functions:

Data Storage: Applications create subdirectories within /var/cache to organize their cache files, with each application responsible for managing its own cache subdirectory and file naming conventions.
Performance Optimization: When applications need frequently accessed data—such as downloaded packages, compiled libraries, or web content—they first check the cache before performing expensive operations like network requests or recomputation.
Automatic Cleanup: System administrators can safely delete cache files during maintenance without affecting application functionality, though applications may need to regenerate data on next use, causing temporary slowdowns.
Subdirectory Structure: Common subdirectories include apt (package manager), man-db (manual pages), yum (Red Hat systems), and nginx (web server), each maintaining their own cached data independently.
Write Permissions: Applications typically require write access to their cache subdirectories, so /var/cache maintains appropriate permission settings allowing services to store data while preventing unauthorized access.

Key Comparisons

Directory	Purpose	Deletion Safety	Typical Size
/var/cache	Application cache data	Safe to delete	500MB-5GB
/var/tmp	Temporary data, survives reboots	Safe to delete	100MB-2GB
/tmp	Temporary data, cleared on reboot	Safe to delete	50MB-1GB
/var/log	System logs and activity records	Should not delete	1GB-50GB
/home	User data and settings	Dangerous to delete	10GB+

Why It Matters

Disk Space Management: Cache files can accumulate over time and consume significant disk space, especially on systems with package managers or web servers actively downloading and caching content.
System Performance: By storing frequently accessed data locally, /var/cache reduces network traffic, I/O operations, and computational overhead, allowing applications to serve requests faster.
Standardization: The FHS specification ensures that all Unix-like systems follow consistent conventions for cache storage, allowing developers and administrators to write portable scripts and management tools.
Maintenance Flexibility: System administrators can safely clean /var/cache during maintenance windows to free disk space without affecting system stability or requiring careful data preservation.

Understanding /var/cache's role in the filesystem hierarchy helps system administrators optimize storage management and application performance. By recognizing which data is truly essential versus expendable, administrators can make informed decisions about cleanup strategies, storage allocation, and system maintenance scheduling. The standardized approach defined by the Filesystem Hierarchy Standard ensures consistent behavior across different Linux distributions and Unix-like systems.