I came up with this topic because i have the same problem.
Please refer to this thread.
I’m at 1.43 version, and my /dev/root is full, meaning ZimaOS-HD is full.
I never got a warning.
I follow some scripts to free some space but that didn’t help.
I managed to update to 1.50 somehow, and now i got a warning. But the system is already become unstable. I wonder where ZimaOS-HD is, and how to fix it.
More is in the thread mentioned above.