I’ve been running OpenHAB on a Raspberry Pi for almost 18 months now, and one of my biggest concerns has been the longevity of the SD card. Over time, I’ve discovered some great tools and techniques to minimize the number of write operations on the SD card, which I’d love to share with you.
First, I use inotifywait to monitor file changes in real-time. This tool helps identify which files are being written to frequently. I’ve found that files like thing_status_storage.json and users.json are updated several times a minute. To reduce this, I’ve moved these files to a zram partition, which is much faster and doesn’t wear down the SD card. Symlinking them back to their original locations has worked perfectly without any issues.
Another tool I’ve found invaluable is iotop, which shows real-time I/O operations. It’s helped me identify background processes that were writing to the SD card unnecessarily. For example, the systemd-timesyncd service was creating a timer file every few seconds. I’ve disabled this functionality by overriding the service configuration, which has significantly reduced write operations.
I’ve also looked into reducing writes from third-party services like Signal. The <uid>.d file was being updated frequently, so I symlinked it to zram as well. This has cut down on unnecessary writes without affecting functionality.
These changes have made a huge difference. My SD card is lasting much longer, and the system runs smoother. I’d love to hear if anyone else has tips or tricks for prolonging the life of their SD cards!
Stay curious and keep tinkering! 