We just tested this by driving the temps up on the drives until the fan went on. The fan finally went on after the drives hit 57C. And that took a minute or so. In the UI, the system temperature still showed normal.
I found out that the text file you were referring to isn’t even in the later firmware, and is not a correct depiction of anything. You should know that It is not uncommon for the drive temperatures to get over 50C, especially when writing data. In SSH you will find three temperatures: the current (system) temperature, and the two drive temperatures. The drive temperatures also show up in the UI. They are the only values that I would be concerned with, and at 57C they are still well below their max temp rating.
My assessment: the drive is working within specs. As long as the drives are NOT going above the 57C, and staying there, then I wouldn’t worry about it.
