What are the most critical systems in a server room?

The design and build of a server room is arranged to provide a secure environment in which to run IT servers, storage and network devices.

• Critical power: is therefore one of the most important systems within a server room to ensure that there is a continuous source of electricity whether the mains power supply is available or not and to protect the IT loads from power outages. Most server rooms will have a centralised or decentralised power protection plan using uninterruptible power supplies, battery packs and a standby power generator arrangement.
• Cooling: IT servers produce a large amount of heat which can become concentrated within a server racks. Within a server room the racks may be arranged into hot and cold aisles, with air conditioning and cooling systems providing cool and humidity controlled air to the front of the server racks. Warm air is exhausted through the rear of the server racks and drawn back to the cooling system. The cool air may be delivered by wall mounted air conditioners, in-row or under-floor computer room air conditions (CRACSs). Without sufficient cooling a server rack housing 5-10kW of IT load could overheat within 15minutes of a loss of cooling and present a fire risk
• Fire Suppression Systems: deliver a fire suppression solution into the server racks or server room space when discharged. The fire suppression agent is chosen to reduce the amount of oxygen within the room to less than 16% (the level below which combustion cannot be maintained.
• Environmental Monitoring: temperature and humidity levels should be monitored in a server room environment to ensure the climate is managed. Sudden changes can indicate a problem with the air conditioning/cooling system which can lead to a downtime and equipment shutdown or a present a fire risk. Other environmental monitored characteristics can include water leakage and smoke detection. An environmental monitoring system will consist of a base unit and sensors and provide alarm alerts when the measured data points fall outside of set thresholds. Alarms can be set to trigger the sending of alert emails, SMS text messages and phone calls, with environmental monitoring devices being access over a HTTPS/HTTP cloud monitoring portals, or reporting via SNMP to data centre infrastructure monitoring (DCIM) packages
• Remote Reboot: KVM switches are used to provide manage and control servers and IT networking devices, and can allow for remote reboots or the powering down of non-essential servers.
• Security: the equipment within a server room are high value items and the data they are processing and services they provide can be mission critical. Doorways are generally controlled via the building’s access control system. This can extend to the server cabinets which will can be installed with access controlled door handles, requiring an authorised MIFARE type card, biometric finger-print and/or keypad pin to gain entry. CCTV cameras may also be deployed to cover doorways, specific server racks and the room itself.

Levels of redundancy may be built into the critical systems to ensure service availability, even during maintenance.