I am running OpenHAB 4.0 on a Raspberry Pi 4 / 8GB in an openHABian environment.
While successfully setting up the Hue Emulation and pairing it with my Rademacher Homepilot, I noticed something scary.
The file hueEmulationUsers.json (in the json database) contains two timestamps: creation of the user, and last usage of this account.
The Last Usage timestamp is updated everytime the Hue API is accessed - which Homepilot does every two seconds.
It actually is written into the jsondb everytime. The current file and the five backups all have the same (minute-resolution) timestamp, and it’s always the current time.
Which means that every two seconds a very few bytes are written onto the SD card - a classical killer scenario - for a value (last usage) I cannot imagine any real use…
Did anyone ever notice that?
In these very investigations I also noticed that it’s more or less the same with org.openhab.core.config.discovery.DiscoveryResult.json. Also located in the jsondb, also updated in a some-seconds-manner.
For now, I moved the two json files and the backup folder into a ZRAM folder (persistence, to be precise) and symlinked these locations in the jsondb. But maybe this would be worth a closer look…?