Server temperature monitoring - sensor locations?

[gshaw]

Just tweaking our temperature monitoring setup at the moment to have a 2nd monitoring device (after one crashed out the other day) but it got me thinking about where to place the sensors.

 

As it stands I've got...

 

- APC UPS temperature sensor mounted high at the back of the rack

- 2 x temperature sensors for the monitoring devices (1 per device)

 

Now I could have them in a couple of places... thoughts on each please...

 

- back of rack (exhaust fan temperature is probably going to be the highest i.e. worst case scenario)

- inlet temperature (front of rack i.e. the temperature of the air going into the servers for cooling)

- top of the rack \ somewhere in the room (ambient temperature but could be affected by the cold air stream from the aircon)

 

Could mix and match i.e. 1 sensor for inlet one ambient etc (also have the option to buy an additional sensor on each monitoring device although may use that for smoke detection)

[Naughty_Nigel]

Ideally, any sensors should be fitted inside the equipment housing. Depending on their type, you may be able to clamp the sensors to the outside of the housing, (relying on thermal conductivity of the metal casing).

 

I would NOT fit thermal sensors in the exhaust air outlet, simply because if the fan(s) fail the equipment will overheat very rapidly, but the sensor will think the air is cool as there will be no hot exhaust air blowing over it! Similarly I don't think it would be a good idea to fit temperature sensors in the air inlet.

 

However, many motherboards and CPU's have thermal sensors built in which could be utilised. Many servers can also be set to shut down in the event of fan failure.

 

I hope that helps.

 

NN