Monitoring server room temperature

I have a small server room with its own AC unit. Recently, the AC died, and the temperature increased from 70 F to > 90 F. We rarely go in this room, so I was lucky that someone happened to notice that the fans were running a lot louder than normal as they walked past the door. It looks like I need a way to be notified when the temperature in that room gets too hot.

What tools are you using to monitor the temperature in your server room? How does this tool notify you of a problem (email, SNMP, etc).

Note: I've read this question on server temperature, but I'm interested in the whole room, not just the inside of a server case.

Edit:

Thanks for all the great responses so far! Many of these products measure much more than just temperature. What else should I be looking at and why?

Solution 1:

Take a look a ITwatchdogs. Their weather goose line looks very nice. They monitor temp, light, sound, humidity, etc.

Here's a list of vendors (not APC) that have other products.

What I use in my data center appears to be a discontinued model. What ever you end up using, make sure that:

• They use SNMP, not some special protocol.
• Have remote temperature sensors. (I don't know if the netbotz do ...)

Currently the temperature monitors are hung from the middle of the drop ceiling.

Using a simple network monitoring application (zenoss, munin, nagios, etc) just monitor for threshold violations and create alerts for your pager/email.

You should also look into buying a handheld thermometer and walk around to every part of your datacenter/comm closet (including corners) to find any hotspots.

Solution 2:

A couple of specific answers and a suggestion ...

1- There are several makers (linked in other answers) of standalone temp and humidity monitoring devices. These are pretty simple .. typically you mount them where you want to monitor, plug them into the network, and configure them to email alerts. They work well.

2- Most servers can raise SNMP alerts when the temperature gets out of spec, and you can use something like WhatsUp from Ipswitch to accept and do something about those alerts.

You should make a point to visit the server room once or twice a day, perhaps on arrival and after lunch, to check on the temp and humidity as well as examine the equipment for lights or status codes that are not normal, unusual noises, etc. If you can't do it then get someone else to do so.