Within the Cloud: Technical Concepts of Cloud Computing - Deploying and Managing a Cloud Infrastructure - page 58

changes dynamically. It is important to have power conditioners , which will ensure that the
power supply is within an acceptable level.
Since uptime is important, uninterruptible power supplies (UPSs) and backup power
generators are a must. UPSs are only there to sustain power before backup generators can
go online, but they should still be able to provide sustained power in case the backups are
running a little late. We do not need to stress how important backup generators are; they are
a necessity for sustained uptime and disaster preparedness, so they must be able to provide
more than enough power and provide it for extended periods. A good way to ensure uptime
is through the use of a redundant power infrastructure, that is, to have two separate power
infrastructures working together or alternately to power the data center. Figure 3.2 shows
two separate power lines being connected to a cloud data center; this ensures that when one
power provider goes down, the other can take over in powering the center.

FIGURE 3.2 Redundant power infrastructure

Diesel generator 1 Diesel generator 2

UPS/conditioner UPS/conditioner

Cloud

Heating, Ventilating, Air Conditioning (HVAC) and Fire Prevention Systems
Data centers are like raging fire pits. If you own a laptop, you know how hot it can get, and
that machine has only one processor module. Now imagine that a single rack can contain 10
or more blade servers a little bit wider than a laptop, thrice as thick, and containing some-
where between 2 and 32 processors (stacking 16 server boards that have 2 processor sockets