Data Center & Colocation center

[denis]

A data centre is a purpose built facility for housing electronic equipment,
typically computers and communications equipment. A bank for example
may have a data centre where all its mainframes, servers, credit card
processing systems etc live. It can occupy one room of a building, one
or more floors, or up to the whole building. They are designed to run
24 hours a day all year round.

Equipment is often racked up in 19 inch rack cabinets which are usually
placed in single rows forming corridors between them. This allows people
access to the front and rear of each cabinet.

Electronic equipment in a confined space generates much excess heat
therefore air conditioning is used to keep the room cool, generally around
17 degrees Celsius.

They will often have back up power. This can include one or more
uninterruptible power supplies and diesel generators located close by.

Data centres typically have raised floors made up of 2 foot (600mm)
removable square tiles. These allow (in theory) all data and power cabling
to be laid neatly and safely in cable trays below.

Data centres often have elaborate fire preventions systems. Using water
on operational electrical equipment can do just as much damage as a fire
so using it is not an option - also water and electricity don't mix well.
Originally halon gas was used in the event of a fire to extinguish flames.
It is an inert gas that pushes all the oxygen out of the room. However this
has now been banned in some countries because of the danger it poses to
people if they are trapped in the same room without oxygen.

Security also plays a large role with data centres. Personal access to the
site is usually restricted to a select few. Video camera survellience and
permanent security guards are almost always present if the data centre is
large or contains sensitive information on any of the systems within.

Prior and during the dot com crash thousands of square feet of data centres
were built in the hope of filling them with servers for web hosting and
application service providers. This demand went largely unrealised.

A colocation centre is a type of data centre.

BambooWeb Dictionary

[denis]

A colocation centre ("colo") or carrier hotel is a type of data center where
multiple telecommunications network or service providers, such as telcos or
ISPs, site their connections to one anothers' networks (points of presence).

Most peering points are sited in colocation centres.

These sites are often used for web hosting.

Most colocation centres have high levels of physical security and multiple
redundant power and air-conditioning systems.

BambooWeb Dictionary

[samuel1003]

Air conditioning and building security services