What directory is fermentation data saved to

Sorry for this newbie question, I wanted to map the fermentation data to a usb flash stick mounted to my pi. Where does brewblox save this data normally and can I redirect it

All configuration can be found in ~/brewblox. History data (shown in graphs) is stored in ~/brewblox/influx.

It’s possible to use a mounted device instead, but very unreliable, and problematic at startup. Is there a specific reason for this? There may be a better alternative.

Bob, early on I had set up my spark and pi to control a chest freezer for fermentation. During my first test run, I had the data sample rate set at the default, and about have way through the test the pi became unresponsive and glitchy. My first though was that because of the size of the data file it might be squeezing the operating system. Just looking for an easy way to separate data from operating system with 2 SD cards

We automatically downsample history data, and only keep realtime data for 24h to prevent memory bloat. In the vast majority of cases, your SD card will die from repeated writes before it overflows with history data.

If your Pi becomes glitchy halfway through operations, it is typically because the SD has reached its limit on possible disk writes, and needs to be replaced.
You could mount a second USB flash drive to spread disk writes between the two, but that introduces problems of its own, especially on reboot.

The recommended approach is to make regular backups of configuration and history data using brewblox-ctl backup save (if you just want configuration), or brewblox-ctl snapshot save (if you also want history data).

If you’d still rather store your history data on a different device, you can do so by overriding the configuration for the influx service.

Stop your services, and then copy the existing ~/brewblox/influxdb/ directory to the desired location. You will need to use sudo to copy the directory.

Edit docker-compose.yml, and add the following service:

      - ./influxdb:/var/lib/influxdb

The entry under volumes consists of two paths, separated with a :.
Do not touch the /var/lib/influxdb part. This is the path inside the service, which will not change.

Replace ./influxdb with the new path of your influxdb directory.
Example configuration (with made-up path name):

      - /media/mystick/influxdb:/var/lib/influxdb

Thanks Bob, based on your input I think I’ll start with the original configuration and then if I run into problems make the changes you suggest, again thanks for the input

Perhaps run a speed test on your SD card. A slow SD card can result in a slow system.

Without a display, you can run it from the command line.

sudo apt update
sudo apt install agnostics
sh /usr/share/agnostics/sdtest.sh