Modern swap management for Raspberry Pi systems, designed to replace dphys-swapfile with a more flexible and efficient approach.
The rpi-swap package provides intelligent swap configuration that adapts to your Raspberry Pi's memory and storage setup. It offers multiple swap mechanisms and integrates seamlessly with systemd's modern service management.
- Dynamic sizing: Automatically calculates optimal swap size based on available RAM and storage
- Multiple swap types: Supports compressed RAM swap (zram), file-based swap, or hybrid combinations
- Early boot integration: Swap is available immediately during the boot process when memory pressure is highest
- Storage-aware: Intelligently chooses swap mechanisms based on your storage type (SD card vs USB/SSD)
- systemd integration: Full integration with systemd's swap.target for reliable service dependencies
- Zero-configuration: Works out of the box with sensible defaults for most Raspberry Pi setups
The system offers four main swap mechanisms:
🗜️ Compressed RAM Swap (zram) Uses a portion of your RAM to create compressed swap space. Ideal for systems with limited storage or SD cards where you want to minimise write wear. The system automatically optimises kernel settings to reduce latency on compressed swap devices.
💾 File-based Swap Traditional swap file on disk storage. Best for systems with fast storage like USB drives or SSDs where you want maximum swap capacity.
🔄 Hybrid (zram + file) Combines both approaches - compressed RAM swap for immediate needs, with writeback storage that allows zram to occasionally move idle pages to disk. This frees up precious zram space for active use while reducing SD card wear through infrequent writes, making it particularly beneficial on memory-constrained systems booting from SD cards. Kernel settings are automatically optimised for low-latency operation with compressed swap devices.
🚫 No Swap (none) Completely disables swap functionality. Useful for systems with abundant RAM or specialised applications where swap is not desired. Any existing swap files will be automatically removed.
The core swap management system that:
- Automatically detects your system's memory and storage configuration
- Creates and manages swap devices during early boot
- Provides writeback capabilities to occasionally move idle pages from compressed RAM to file-backed storage
- Replaces the functionality of
dphys-swapfilewith a more modern approach
Infrastructure for reliable loop device management:
- Creates stable, persistent names for loop devices based on their backing files
- Ensures loop devices can be reliably referenced in systemd units and scripts
- Provides the foundation for file-based swap functionality
While dphys-swapfile has served Raspberry Pi well, modern systems benefit from:
- Better memory utilisation: zram compression uses spare CPU cycles to make better use of your available RAM
- Reduced storage wear: Especially important for SD card longevity
- Faster swap performance: Compressed RAM swap is much faster than disk-based swap
- Automatic performance tuning: Kernel parameters are optimised for low-latency operation with zram devices
- Modern systemd integration: Full integration with systemd's swap.target and service dependencies
- Multiple swap mechanisms: Choose the best approach for your specific hardware and use case
- Hybrid capabilities: Advanced writeback features to optimise memory usage over time
For most users, rpi-swap works automatically with no configuration required.
Advanced configuration is available through configuration drop-ins as documented in swap.conf(5) and will typically be managed through raspi-config in future Raspberry Pi OS releases.
While systemctl daemon-reload will regenerate the systemd units, it won't stop existing swap units or start new ones. The swap generator runs during early boot when memory pressure is minimal - attempting to reconfigure active swap later can cause system instability.
Configuration files are located at:
/etc/rpi/swap.conf- Main configuration file/etc/rpi/swap.conf.d/*.conf- Drop-in configuration files (recommended for local changes)
For examples and detailed configuration options, see man swap.conf.
- Raspberry Pi running a systemd-based Linux distribution
- systemd-zram-generator package (automatically installed as dependency)
- Modern kernel with zram support (standard in Raspberry Pi OS)
This package is designed to be included by default in future Raspberry Pi OS releases as the standard swap management solution, providing better performance and reliability than the current dphys-swapfile approach.
For technical documentation, see the included manual pages: man rpi-swap-generator and man swap.conf