Is smartd really reporting this drive is too hot?

Solution 1:

That is just SMART attribute value. It is not the temperature in any regular unit. (it is more like a number between 255 (really really cold) and 0 (really really hot), depending on drive what is hot and what not)

If you want to see the temp of your drive use smartctl -A /dev/sdx

You'll get table like this:

ID# ATTRIBUTE_NAME          FLAG     VALUE WORST THRESH TYPE      UPDATED  WHEN_FAILED RAW_VALUE
194 Temperature_Celsius     0x0022   107   097   000    Old_age   Always       -       45

RAW_VALUE is what you're looking for ... (my drive is quite warm at 45°C)

VALUE is the attribute value and when it gets below THRESH, the drive is getting ready to ask for replacement. (Not all attributes have threshold, just like my temperature)

With regards to what is hot and what is not, it really depends on drive. There is a somewhat dated paper from Google on drive failure rates, which states that drives around 40°C have the lowest failure rates (at least for google and in 2007). I remember reading another paper (can't find it now) which stated, that high temperature is not a problem for hard drive. Sharp and frequent temperature changes can cause the disk to fail sooner. So as long as the drive temp is pretty stable (you can monitor that using something like munin), you should be fine.

smartd is reporting any changes in attributes. It does not mean that there is something wrong.