The increased utilization of blade servers has caused the control of heat and humidity in the server racks to become much more critical than previously. These units increase the density of the equipment in each rack and therefore the heat generated. Alarms are necessary at the rack level because a single server overheating will not raise the ambient room temperature enough to set off the room alarm sensors. These rack alarms can provide early problem warning and prevent server damage and the associated network problems in a timely fashion.
These alarms can be at the rack, or by email, or by SNMP traps, or by all three methods depending on the system. There are several different types of sensor systems from several different manufacturers, available at present. One of them is a compact environmental monitor with one onboard temperature sensor and in addition the ability to support up to 16 remote sensors. The system is very small so you don't have to change your system. If you receive a problem alert, you are able to identify the rack and power strip having the trouble, and turn off the individual outlet or reboot it.
Another power management and control system available is able to track temperature, humidity, airflow, and water at various locations from 15 to 100 feet away. This system needs only limited rack space and can control individual power receptacles. Another system on the market utilizes two sensor probes in each rack, one in front, one in back, to better measure the environment in the rack. This gives you a thermographic view of the temperature range in the rack and can be displayed in color for all the different racks in the computer center. This information can be used to determine the size and location of any additional A.C. or fans or blowers needed to correct a cooling system. It can also assist in the rearrangement, if necessary, of the rack layout and separation of a cold aisle/hot aisle system or any rack system, or when additional racks are added to a functioning system.
The control of heat generation and temperature in the data center continues to be one of the most critical areas. The monitoring of the environment has gone from the room, to the zone, to inside the individual server rack to give a much more precise picture of what is happening and allow better response to emergency conditions.
