Update Module and Yocto


We use mender and yocto to generate our complete image but each updates are large to deploy through 4G. Our application is located in a /opt/ folder.
Is it possible to use the directory update module to make some application updates in between large image updates without any conflicts ?

Best regards

Hi @Austriker :slight_smile:

It depends on what you mean by ‘conflicts’. In general any update that is not a full-image update will result in a state, which is no longer fully tracked by the original image that you installed. If you mean, that this is possible with Mender, without breaking the device, then yes. Directory updates can also support rollback. Which means, that if something goes wrong during the install, the module will clean up after itself. Not though, that this also means, that no single update-artifact no longer contains the entire state of the system on your running device. For this a full image install is needed :slight_smile:

Does this make sense?

Directory update module

Hi @oleorhagen

Yes I think it makes sense I wanted to be sure that the following scheme is possible:

  • v1.0 image update
  • v1.1 directory update
  • v1.2 directory update
  • v2.0 image update
  • v2.X directory update

My app is contained in both directory and image update.

Yes, that will work just fine. However, if the directory updates are contained in the rootfs, then the v2.0 image update will overwrite your changes.