Server Room Temperature Monitoring using SNMP sensors

Server Room Temperature Monitoring header image
5 min

Recently we’ve seen quite a few questions on server room temperature monitoring posted in the r/msp Reddit Group. Quite a few people have been querying which tools are best for monitoring server room temperature and humidity. 

LoneStarr21 writes on Reddit:

“I need to keep an eye on the air temperature in a small server room.

Can anyone recommend a sensor that I can access remotely or that can send me alerts? Maybe something that plugs into the network, server or workstation that will send me the data?”

Domotz is the perfect network management software to use for server room temperature monitoring. The software can easily be configured to send you and your team alerts when SNMP temperature and humidity values rise or fall. 

To help you get started, I’ve created a 5 step guide on how you can easily set-up Domotz and SNMP sensors for server room temperature monitoring.

Required software/hardware for server room temperature monitoring: 

What this guide covers: 

  1. Choosing your sensors for server room temperature monitoring
  2. Room Temperature Sensor Set-up
  3. How to find the OIDs associated with your sensors
  4. Setting the OIDs in Domotz SNMP/TCP Sensors 
  5. Configuring Alerts for Room Temperature and Humidity Monitoring

By the end of this article you and your team will be able to get alerts when environmental sensors, such as temperature and humidity, are beyond expected thresholds.  

1) Choosing your sensors for server room temperature monitoring 

There are several different Temperature and Humidity sensors on the market.  In many instances, you can also find uninterruptible power supplies and power distribution units that will have external sensors available for temperature and humidity as well.  For the purpose of this article, I purchased a Vertiv Geist Watchdog 15 Environmental Monitor, which I have found to be commonly used in server rooms environments.  The process I’ll walk through to enable this device in Domotz is similar to other solutions.

2) Room Temperature Sensor Set-up

I first need to ensure the sensor was set-up for proper network connectivity.   In this instance, I wanted to enable the sensor with DHCP.   Domotz discovered the Geist sensor within 30 seconds, so I was able to easily access the agent through the Domotz’s connections tab.  I also took note of the sensor’s IP address such that I could access it directly through VPN on Demand.

Server Room Temperature Monitoring Vertiv Dashboard

While in the sensor’s configuration page, I ensured that the SNMP community strings were set to known values.  In this case, and this is common with many systems, I left the default public/private community strings.   If you are in a business environment and are concerned about security, you should strongly consider disabling SNMP v1/v2c and enabling the more secure SNMP v3.  For this example, knowing the community strings will be enough.

Server Room Temperature Monitoring Vertiv Dashboard 2

Vertiv did a really nice thing on the SNMP page and they provided you with a link to download the MIB files, which also includes a CSV file showing the specific OIDs for this device.   I went ahead and downloaded the MIB so I can load it into my MIB Browser to validate the readings.

After configuring the sensor for the network, I wanted to validate the MIB/OIDs.  

3) How to find the OIDs associated with your sensors 

I’ve come accustomed to using iReasoning’s MIB Browser. It works well and is free for personal use.  At this point, I want to tell you that I had installed the temperature/humidity sensor in our IoT Lab, which was offsite from where I am writing this article.  Because of this, I leveraged Domotz’s VPN on Demand to use the MIB Browser to gain direct access to the sensor.  After creating the VPN Tunnel, I was able to input the sensor’s IP address (noted earlier) directly into the MIB Browser.   I also loaded the MIB library provided from the sensor’s SNMP configuration page.   It is OK not to load the MIB library, but then you will not see the names associated with the variables, it will only provide you with the OIDs, making it less human readable.

After inputting the sensor IP address and selecting Walk, the MIB Browser returned the complete list of OIDs available to this sensor.

It was easy to see that at the bottom of the list, the sensor’s temperature, humidity and dew point were provided and read correctly.  In case you were curious about the numbers, the CSV file and the MIB Libraries description tells you that the integer32 number is representative of 1/10th degrees, so in the reading from my sensor, 986 is 98.6 degrees Fahrenheit (healthy for a human, but probably a little warm for a cabinet/rack).

Display of OID's associated with the SNMP sensors for server room temperature and humidity monitoring

Image of current reading for SNMP temperature sensors: 986 is 98.6 degrees Fahrenheit

4) Setting the OIDs in Domotz SNMP/TCP Sensors for Room Temperature Monitoring

Now that you have found and validated the OIDs associated with the sensor, you can go to the Domotz UI and find the device.

Domotz dashboard

When you click on the “SNMP/TCP” tab, you will be taken to the page where you can set-up the individual sensors. By clicking on the “Add an SNMP Sensor” button, you can select potentially available OIDs from common MIBs, or you can Manually define an SNMP Sensor.   Because this sensor uses private MIBs, I manually added the SNMP Sensor.

After several hours, you can see how Domotz continued to aggregate data from these sensors and made the current reading and historical graph of the values available in the user interface.

Aggregating data on the Domotz dashboard for SNMP temperature and humidity sensors

I provided a Sensor name and description which is used in the Domotz UI.   This name and description should be readable and understandable to you and your team.   I copied the OID from the MIB browser and placed it into the OID section and selected “Numeric” as this is a numbered result.   NOTE: you may notice that there is a “.1” added to the end of the OID, compared to the OID and Description associated with the CSV/MIB Library.  With the way that MIBs and OIDs work, the “.1” shows the result for this OID.   Domotz needs the “.1” to read the result.  You should also note that Domotz does not require the “.” to be placed at the beginning of the OID string.

I added the humidity and dew point sensors in the same manner.  After returning to the SNMP/TCP page of the sensor, you can see that Domotz started to collect data associated with these sensors.

Domotz dashboard aggregating SNMP temperature and humidity sensor history data over several hours

SNMP sensor data aggregated over a period of several hours in a historical graph on the Domotz dashboard

5) Configuring Alerts for Server Room Temperature and Humidity Monitoring 

Under the Alerts section of the sensor, you can set up a custom alert.

Setting up alerts for server room temperature monitoring from the Domotz dashboard

As you scroll down the page, you find the SNMP Sensors section and by clicking “configure an SNMP Alert” you will see the sensors associated with the device that I just created.

Viewing the SNMP sensor associated with the device from the Domotz dashboard

In my example here, I took the temperature sensor and set an alert to trigger when the sensor “is greater than” 105.  I gave it a name to be human readable and clear when the alert comes across in an email. As a quick reminder, remember that the sensor is measured in 1/10th degree increments, so you will notice I set the Domotz event trigger to 1050.

Here you can see that the SNMP Sensors section now has an email alert associated with this type of event.

Choosing notification preferences for SNMP sensor alerts when temperature and humidity values rise and fall

You can set up SNMP Sensor triggers to Shared Alerts in a similar manner.  With Shared Alerts, you can automatically open tickets, send notifications through WebHooks, such as MicroSoft Teams or Slack, or general emails as appropriate.

Setting up shared alerts when server room sensors humidity and temperatures values rise or fall

Closing thoughts on Room Temperature and Humidity Monitoring with Domotz 

As you can see it’s fairly easy to set-up Domotz for server room temperature monitoring so you can get alerted when humidity and temperature values of a room rise or fall.

This is the perfect feature for keeping the important gear stored in a server room safe from the elements.  

Get started with Domotz network management software by installing it for free for 21 days on Windows, Linux, Raspberry Pi, NAS (Qnap, Synology, ReadyNAS) or our box. 

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