config.txt changes are not applying to the host

Product support
1

I have a fleet where I’ve updated the default device configuration with a variable am not seeing the update appear on the device. Is my understanding correct that device configuration variables prefixed with BALENA_HOST_CONFIG_are applied to the config.txt automatically (i.e. setting BALENA_HOST_CONFIG_isolcpus to 3 should add an entry into the config.txt with isolcpus=3)?

I am trying to set the isolcpus, trying both RESIN_HOST_CONFIG_isolcpus and BALENA_HOST_CONFIG_isolcpus. I’ve tried to reboot via the console and power cycling. The fleet has 3 devices, all are identical Raspberry Pi 5s running the latest Host OS (balenaOS 6.9.4+rev2). 1 device is in development mode, the other 2 are in production, but all are experiencing the same issue.

On the development device, if I manually update the /resin-boot/config.txt with the value, it works as expected.

2

Hi @bobbrez, and welcome to the forums!

Your understanding is correct: as per our documentation [1] any variable prefixed with BALENA_HOST_CONFIG_ added via the configuration tab on the dashboard will show up in config.txt. I just tested on a raspberry pi 4 device with BALENA_HOST_CONFIG_isolcpus and it works as expected.

Note that the change is visible in /mnt/boot/config.txt, whcih is the config file used by the OS, and not /resin-boot/config.txt which is a default file that is populated upon provisioning.

When you look at /mnt/boot/config.txt are you able to see the value isolcpus=3?

[1] Advanced boot settings | balena