The Hostway Blog

Data Center Tour Part 1: Introduction

Modern data centers are often compared to military bases, with perimeter fences guarded by security staff, large windowless concrete buildings and lots of surveillance equipment. Looking back at how they developed, that’s hardly surprising. Here we take a brief look at the origins of the data center and how they have changed over the years.

Early Computer Rooms

Early computers were expensive, complex and large machines. Cabinets housing individual components were often larger than fridge freezers and were joined together with large amounts of heavy cabling. They required enormous amounts of energy to run, and generated a lot of heat. Thus air conditioning and climate control were of paramount importance from the outset, with some components being water cooled. Computers were often developed for military purposes too, thus security was another major consideration.

Perhaps the best way to get a picture of early mainframe computer rooms is to imagine the banks of consoles with flashing lights, buttons and switches as seen in 1960s and 70s sci-fi programs. A contemporary 1970s description by a BBC Radio Presenter of an early computer center in the UK tells us:

“It was about three times the size of an average lounge and people at what looked like large filing cabinets, some with flickering lights which were going mad, some with glass fronts behind which tapes were whirling back and forth, and the rest with tightly shut doors, which …apparently were the homes of memories and mass storage units.”

From Mainframes to Minicomputers

By the 1980s mainframe computers whose components would take up the whole room had been joined by mini computers, where the components had been developed to such an extent everything could be housed in a single cabinet, even if these were still the size of commercial chest freezers or washing machines. Pictures of late 1980s mainframe and minicomputers posted by one long serving computer operator show mini computers that look like a mechanics’ workbench, tape drives the size of vending machines and disk drives that look more like large laser printers.

From Consoles to Servers

During the 1980s, computer components were developed that were smaller and more powerful, until the microcomputer or desktop PC became available. The early ones were sold in kit form mainly to home enthusiasts, and were temperamental at best. Eventually, though, these became more reliable and software was developed that meant they found their way into businesses that could not afford either mainframe or mini computers. Slowly the ‘dumb’ terminals connected to a mainframe computer were replaced with a series of microcomputers, each with their own processors and hard drives. However, since this segmented information, issues of data integrity and duplication soon led to the development of networks of server and client microcomputers, and the servers often ended up housed in the computer rooms either alongside or instead of the mainframes and minicomputers, often in 19” rack mounts that resemble rows of lockers.


The biggest change in the nature of data centers came as a result of the lifting of restrictions on commercial use of the Internet, though. Although Symbolics Inc registered the first commercial domain, in 1985, it was another 10 years before the National Science Foundation ended its sponsorship of the Internet backbone, and the Internet became truly open to commerce. In 1995 there were only an estimated 16 million Internet users worldwide according to Internet World Stats.

Initially only the largest companies with their own data centers created websites. One of the biggest challenges facing smaller firms wanting to register a domain name and create a global presence on the Internet was the cost involved with keeping a Web site available online 24/7.

Between 1996 and December 2009 Internet usage expanded to 1.8 billion worldwide, and by the end of 2009 there were over 112 million domain names registered. This staggering growth has fuelled the development of modern data centers as SMEs have outsourced their Web hosting requirements, either sharing resourced on shared servers, leasing dedicated servers or collocating their own equipment in data centers that are managed and maintained by data center staff, leaving them free to concentrate on applications development.

This growth has led to a need to house more and more capacity into the same space to reduce server sprawl and to limit the increase in electricity needed to power and cool the data center. So much so that modern mainframe computers, which had been described as the dinosaurs of computing, are re-emerging in many data centers. That’s because they are now quite similar in size to a rack mounted bay of servers, and a single mainframe, thanks to virtualization technology, can run as dozens if not hundreds of virtual machines.

Another feature of the early computer rooms returning to the data center are water or liquid based cooling systems, as the heat produced by chips and other components reaches the limits of what air based cooling systems can control. In some ways, it seems as though the data center has come full circle, with the focus on ever smaller yet higher capacity components. Now the data center is poised for another revolution, this time with the focus on ever more energy efficient yet high performance equipment.

Read the complete series:
Data Center Tour Part 1: Introduction
Data Center Tour Part 2: Meet the Staff
Data Center Tour Part 3: Physical Security
Data Center Tour Part 4: Redundancy
Data Center Tour Part 5: Servers