Hello,
We are investigating updating our devices from Mender 4.0 to Mender 5.0. One part of this process is checking if downgrades are possible as we occasionally need to roll back a device to an older version of our software.
While testing this we found the following error:
“Could not fulfill request: Operation not supported: State data has a version which is not supported by this client”
It looks like standalone_data_version is changed in 2c1d92212dcdba383ce0872ad108b3f6cde8c0f9, and versions 4.0.x of Mender do not handle the new data version. This leaves the device in a “confused” state when installing a Mender 4.x over a 5.x, it seems we can’t commit the update (and possibly rollback also doesn’t work well, but I will check that with my colleague who did the test).
This seems to not be mentioned in release notes. But, if I understand right it affects only standalone mode (updates through Mender server should be fine), can you confirm that?
Is there a risk that this will cause problems in rollback of an install of 5.0 back to 4.0?
Is there a way to ensure some level of backwards compatibility? For example introduce a 4.0.x version that can read (but not write) the new format, so we can first update to that and only later to 5.0?
In case this matters: we are using the Yocto layer integration with Yocto kirkstone on custom hardware. We are using both standalone mode and online mode depending on the scenario.