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?
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:
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.
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.
+1 to Joseph Kern's answer. We use one of ITWatchdog's systems,but I've used other systems as well, and the general idea is great.
ITWatchdogs, and a lot of other vendors, make use of the Dallas 1-wire bus to drive their sensors. The actual sensors are available from Farnell etc for very low prices, and they basically attach to a piece of cat3 cable. You can combine an ITWatchdogs (or similar) system with a lot of hand-assembled 1-wire sensors for a relatively cheap solution.
There are also standard RS232 interfaces to the 1-wire bus, (such as this one) with varying levels of complexity, which mean you can directly attach monitoring gear to servers, in case you don't want to run additional gear (remote POP with only one machine, for example)
We use the MiniGoos products from http://www.itwatchdogs.com/. I will admit I wasn't involved in the evaluation process for these, but I really like the product. They allow multiple temperature sensors and they have some nifty add ons like air flow monitoring (which we aren't currently using) and things like door open/close detection (which we are). They have an HTTP interface which could be scraped if you wanted, but also support SNMP traps and polls. We plugged it into nagios and it worked like a champ.
I also second and extend a comment josephkern made in his answer. In addition to walking around with a thermometer to get a feel for the temperature pattern in the room, buy some cheap non-connected thermometers and hang them from the ceiling. They're great backup for reporting thermometers, and you'd be surprised how often a problem will be spotted by a human glancing at the therm as they walk in and out of the room before the warning range of the monitoring thermometers is crossed. The earlier you diagnose an AC/HVAC problem, the longer you will have to fix it before you start damaging components, having to shut down machines, or having machines shut down on their own to protect themselves.
If you want a cheap solution, you can buy USB thermometers for about 10USD. I've got a TEMPer device. I've not got around to using it yet, mostly because it's not entirely supported under Linux. Tollef Fog Heen wrote some support, but I haven't checked to see if it's in the kernel yet. It does ship with Windows drivers, so it just a matter of hooking it up to your monitoring. :)
A more inexpensive route would be to use a temperature monitor that hooks into your buildings security system. If the temperature reaches a set level, people on the security system call list are contacted.
We have a similar setup (private suite at a data center with its own A/C to cool the room) and use TemPageR from AVTECH to monitor the temperature in the room and get e-mail/SMS notices if the temperature goes over a certain threshold. We use the internal probe to monitor ambient temperature, and a remote probe to monitor the air coming directly out of the A/C blower to make sure it's cold.
We like this because it's a completely standalone device that doesn't need to be connected to software on another server to function. AVTECH makes a full line of environmental monitoring systems including temperature and water sensors.
Although we have room-wide environmental alarms not everyone has that luxury, what I'd suggest you do is look at the servers you have, many already have temperature sensors that, in conjunction with free systems management software, allow for SNMP-traps and emails to be sent once these sensors go over a particular level. In particular I know that both HP and IBM servers have these and I'm pretty sure Dell do too. Let me know what make/models you have and I'll try to dig something up.
A guy I know has a probe with GSM transmitter on it stuck to one of the walls in the server room. It basically calls him if something is seriously wrong, and sends SMS if it's a minor problem.
I'm going to buy one myself, I'll post back when I have the product name.
Edit: It's something like the SCOM-100 from Infinite Ltd.
There's also the LM Sensors project.
http://www.lm-sensors.org/