log2ram is a utility specifically designed for Linux-based systems, particularly single-board computers like the Raspberry Pi, to mitigate wear on their SD cards. It achieves this by strategically minimizing write operations to the SD card, a component known for its susceptibility to degradation from frequent write cycles. The core functionality involves storing system logs in RAM (Random Access Memory), a much faster and less wear-prone storage medium. This approach not only significantly extends the lifespan of the SD card, as detailed in https://linuxfun.org/en/2021/01/01/what-log2ram-does-en/, but also enhances overall system responsiveness due to the inherently faster read and write speeds of RAM compared to SD cards.
Although, log2ram is primarily recommended for Raspberry Pi and systems which run off an SD card, but it can be installed on any Linux system.
log2ram operates by keeping system logs in a RAM-based filesystem (tmpfs). To persist these logs, it periodically flushes or syncs the contents of this RAM filesystem to the actual storage media (typically an SD card) at a defined interval. This synchronization ensures that logs are not completely lost upon a system crash or power failure. The frequency of this flush operation is configurable, allowing users to balance the need for up-to-date persistent logs with the desire to minimize write operations to the SD card. Additionally, log2ram might also trigger a sync under specific conditions, such as before a system shutdown, to ensure data integrity.
Overall, log2ram is a simple yet effective tool to optimize Raspberry Pi and other Linux systems by protecting SD cards from premature failure due to excessive logging writes, while also enhancing system speed.
Installation is pretty straight forward on Debian based system, where you can install from the repository.
echo "deb [signed-by=/usr/share/keyrings/azlux-archive-keyring.gpg] http://packages.azlux.fr/debian/ bookworm main" | sudo tee /etc/apt/sources.list.d/azlux.list
sudo wget -O /usr/share/keyrings/azlux-archive-keyring.gpg https://azlux.fr/repo.gpg
sudo apt update
sudo apt install log2ram
For manual install & more information refer to https://github.com/azlux/log2ram?tab=readme-ov-file
Post installtion you may tweak the log2ram config file, to adjust the amount of RAM allocated for log storage to suit your system’s resources and logging needs. The configuration also allows you to enable or disable log compression. If compression is enabled, you can typically select from various algorithms that offer different trade-offs between compression ratio and processing overhead. For instance, lz4 is the default and generally recommended for its excellent balance of speed and compression, while zstd can be chosen for achieving maximum compression at the potential cost of slightly higher CPU usage. Here is my log2ram.conf
SIZE=512M
PATH_DISK="/var/log"
JOURNALD_AWARE=true
ZL2R=false
COMP_ALG=lz4
LOG_DISK_SIZE=512M
To further optimize RAM usage, you can configure log2ram to manage only active log files. By default, log2ram mirrors the entire /var/log directory in RAM, which includes both actively written logs and older, rotated log files. Retaining these rotated logs in RAM can consume considerable memory, especially if you have numerous or large historical log files.
However, you can instruct log2ram to exclude these rotated logs by utilizing the olddir directive within the system’s log rotation configuration (managed by logrotate). The olddir directive allows you to specify an alternative directory or even a different partition on your SD card where rotated log files will be moved instead of remaining in /var/log.
By manually editing each relevant logrotate configuration file (typically found in /etc/logrotate.d/) to include an olddir directive pointing to a separate location (for example, /mnt/log/rotated_logs), you ensure that once logs are rotated, they are moved out of /var/log. Consequently, log2ram will only load the active logs present in /var/log into the RAM disk, significantly reducing RAM consumption.
We hope this advanced tip enhances your log2ram experience and contributes even further to the longevity of your SD card. Happy optimizing!
