Data Centers – An Introduction

Data Center RoomIn today’s world, all of us are well aware of the extensive growth in the IT Industry. Our day to day life is highly influenced by IT industry, be it withdrawing cash from ATM’s, paying bills over internet or shopping online. These advances have our lives easier and more comfortable.

We all know about the software, since it is the most popular part of the IT we come across. We use it in various forms like websites on internet, mobile application etc. But here, I’m going to talk about the underlying hardware infrastructure which makes it all possible. Hardware is the base on which software runs to provide all the services.

Let us discuss about the term Data Centers. Data Centers, generally speaking are server farms with associated components like storage devices, networking devices and adequate non-IT infra such as air-conditioning etc.

I’ll discuss the components in detail one by one. To ignorant, Data Centers may seem as a building full of computers and other electronic devices but trust me; these are extremely dense investment of money (if you talk in terms of money invested per sq. foot) and are guarded like treasures.

A data center provides the compute power to run software. This software can be for various purposes/types like- hosting websites, banking software, billing software for a state electricity board, reservation system for railways/airlines etc. Now we see, these types of software serve a huge number of users, thus requiring a huge compute power to handle them. Here’s where data center comes in picture.

Components in a data center can be broadly classified into two types- IT infra and Physical infra. Let’s discuss these in detail.

IT infra can be broadly classified into following components-

  • Servers
  • Storage and Backup
  • Networking
  • Security
  • Software
  • Control Center

Let’s start with servers. Servers are the most important components of a data center. Now, I suppose most of the people reading are familiar with the term. So proceeding further, servers come in various form factors- tower, rack and blade. Of these, rack and blade servers are the prominent one’s used in data centers. The servers are mounted on a rack (Rack is a frame used to keep mount servers.) Servers may be selected depending on various conditions such as the application they will run, space requirements etc. More on this later, though.

The next component is storage. You may ask; why do we need external storage? The answer is pretty simple. The amount of data handled by these servers is simply too big to fit in hard disks they come equipped with. The internal hard disks of the server generally contain the OS, the application running and some other small software. The actual data normally resides on external storage. The external storage may be classified into two types-Online and Offline. Online storage is directly accessible by the servers and contains the production data. Online storage may refer to DAS (Disk Attached Storage), NAS (Network Attached Storage), SAN (Storage Area Networks) etc. Offline storage refers to the storage used for backing up the data; that is used for recovery in case of failure in online storage. Offline storage may refer to Tape drives, Tape libraries etc.

Now we’ll discuss about the networking components. Networking components include-switches, routers etc. These are used to connect the components together in a network. The networking components offer connectivity on various mediums such as-Fiber Optics, Ethernet etc. and provide large bandwidth for the smooth flow of data within and to/from the data center. Also, a data center will have its own dedicated connection to connect it to the internet.

Security devices would include various components like Firewall, IPS (Intrusion Prevention System), IDS (Intrusion Detection System) etc. The data stored in data center is very valuable and is heavily guarded from unwanted attack/access through the use of the above mentioned devices. All these are now individual appliances with dedicated OS and software running on them.

The software is the application running on the installed hardware infrastructure. The software may be ERP, Banking Solution, OLTP etc.

The Control Center is the place from where the entire data center is managed and monitored. It is manned by experts 24×7 and has terminals which are used to remote login into the servers and the system. It also has LCD panels or Projector Screens to display vital information about the servers.

Some special features of IT infra at Data Center can be summarized below:

  1. The components are generally come equipped with RAS features. RAS stands for Reliability, Availability and Scalability. Reliability and availability refer to the equipment being able to survive a failure of components and continue delivering services. This is generally achieved through redundancy, clustering etc. E.g. Servers may be implemented in clusters; switches may be in pairs etc. It is important to note redundancy may be provided at various layers.
  2. Care is taken to avoid a SPOF (Single Point Of Failure) in the entire architecture of data center. There should not be any such component in data center whose malfunctioning may cause DC (Data Center) to shut down.

In rest part of write up I’ll cover the Physical Infra of the Data Center. The Physical infra includes the following components.

  • Electrical & Civil/Interior Build
  • Power Supply/Backup/UPS
  • DG sets
  • Precision Air Conditioning
  • Comfort Air Conditioning
  • Access Control System
  • CCTV Monitoring System
  • Structured Cabling
  • Water Leakage Detection System
  • Rodent Repellant System
  • PA systems
  • Fire Detection System
  • VESDA Systems(Very Early Smoke Detection & Alarm)
  • Fire Suppression System
  • Building Management System

The structure housing the data center is built according to various standards. It has ability to withstand disasters such as earthquake, storms etc. Fire resistant materials are employed wherever possible.

Power supply is a very important and critical parameter in the running of data centers. Data centers are heavy consumers of electrical power. Usually a data center will have separate power link from different sub-station of different vendors so that in case if one link fails, other can still take care of the power requirements. To meet with a short duration outage in power supply and to keep systems running 24×7, DC’s use UPS (Uninterrupted Power Supply). These UPS are powered by a battery bank, whose capacity is decided using the power ratings of total installed components.

To deal with long duration of power failures, diesel generators are utilized which are generally automated (means they start up automatically in case of power failure)

Precision Air Conditioning systems are installed to keep temperature and humidity constant in places where equipment’s are installed. As you must be aware, processors and other components produce huge amount of heat while working, they need to be cooled to keep working constantly 24×7. A data center has specialized PAC to achieve the cooling. The cooling may be achieved through air/liquid etc. Humidity and dust particles are also monitored by PAC unit. It is generally installed in a redundant fashion because failure of PAC can bring the entire data center down.

Comfort air conditioning is deployed to cool the areas occupied by the human beings. Control Center is an example.

Access Control System is very vital as it helps to keep the data center free of intrusion by trespassers. Different types of security devices ranging from simple RFID based systems to advanced Biometric Systems (Which scan fingerprints/retina) are utilized.

CCTV Monitoring is used to record the video in the premises of the data centers. This is done for the security purposes.

Structured cabling is used to keep the interconnecting wires in the Data Center organized. Structured cabling is generally done under the false floor/ceiling. It uses standardized building blocks such as wires etc.

Water Leakage Detection System helps to detect the leakage of the water inside the data center premises. Water may be harmful to the electrical components installed inside data center.

Rodent repellant system is used to keep out rodents like rats out of the building so that they do not cause any harm to the systems. It generally uses ultrasonic sound waves to keep rodents away.

PA Systems are public announcement systems which are installed in data centers to convey messages throughout the data center.

Fire detection system is used to detect fire in the building and it uses special type of fire extinguishers to put out the fire. Generally gas based fire extinguisher is used(inert gases) to put out the fire as sprinkling water on electrical systems may cause them to malfunction.

VESDA stands for Very Early Smoke Detection and Alarm systems and it is used for detection of smoke within the data center and raise alarms.

Fire suppression systems are used to put out fire in the data center so that none of the components are affected in an adverse manner. They use inert gases instead of water etc. to suppress fire and minimize the damages.

Building Management System is a computer based system which manages and automates the electrical and mechanical systems in the building. Such systems include- Power, Heating/Cooling, Ventilation, Security etc.

Some references-

  1. Data Centers
  2. Servers
  3. DAS
  4. NAS
  5. SAN
  6. Tape Libraries
  7. Firewall
  8. IPS
  9. IDS
  10. Structured Cabling
  11. Building Management System
  12. Access Control System

P.S. The references quoted are from Wikipedia.com and they should not be treated more than a mere introduction to the subject matter. For deep study, I’d advice more research on the internet and discussions with experts on the subject matter.

Also, this article is just an introduction to the data centers, I'll try to discuss all the components in details in next blogs!



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