D ATA C E N T R E S
A Need for Structure
Data Centre Testing
By: Dave Wolfenden of Mafi Mushkila and Karl Sullivan of Optimum Power Services
Introduction
Dave Wolfenden and
Karl Sullivan examine
a four level approach
to testing a data
centre.
Any form of testing needs a structured
approach. It doesn’t matter whether
you are testing software, hardware, a
data centre or doing the MOT on a car.
Without a structured approach it is easy
to miss things that could later turn out to
be a major challenge. Historically, when
testing data centres most of the attention
has been on the data halls. In many
respects that makes perfect sense. This
is where customer equipment is housed
and where the majority of changes are
made. The problem is that there are
very few testing companies that have
chosen to cover the entire data centre,
from generators to switches and internal
lighting. Cloud computing and data
sovereignty have intensified the building
and refurbishment of data centres.
electrical switchgear. From there the
attention moves to the data halls. The
reason for this is that the main power
circuits into the premises rarely change.
The same is true of the generators
and often of the batteries for UPS
emergency backup.
What does change regularly is
the inside components, such as the
hardware in the racks and even the
racks themselves. The re-emergence of
the mainframe as a two rack unit and its
increasing uptake alongside the rapidly
growing converged appliance market
means that devices are now drawing
more power than ever before, creating
new heat spot problems. This means
that internal testing is no longer a
one-off; instead it needs to be a
continual process.
A Four Stage Approach
Level 1: Capital Cooling
In order to properly test a facility it’s
necessary to start from the outside with
the capital plant, such as chillers, coolers,
generators, transformers, UPS and
The type of cooling chosen will
determine the cooling equipment
that is to be used. IT is key to test
the equipment beyond the normal
temperature range in which it will
operate. For example, if you expect
to be cooling a heat load of 50C, you
will need to heat the coolant, be that
water, glycol or an alternative, to at least
that temperature using, for example,
industrial boilers.
With the extra heat that is generated
by new generations of hardware
and greater density of deployment,
it is important to consider testing
substantially beyond the initial expected
heat load. Once the coolant has been
heated to the required temperature
measure how long it takes the cooling
and chiller systems to cool it. Depending
on the type of cooling, external
temperatures can affect the time taken
for the coolant to drop to the required
temperature.
One area that is often neglected is
inline temperature testing. Temperature
is often measured at the level of
the equipment, rack, enclosure and
even dat a hall. However, installing
temperature monitors inside the air
system itself will show if there is an
imbalance in the way air is being moved
through the system allowing engineers
to quickly remediate.
Level 2: Power Systems
Cloud computing and data sovereignty have intensified the building and refurbishment of data centres
36 NETCOMMS europe Volume V Issue 6 2015
Generator testing can often be
very difficult. You need to create
representative load banks for the
equipment the generators will have to
power. These need to be spread around
the facility to provide a reasonable
representation of how the loading
is expected to look once the data
centre opens. The goal is to test both
the generators and spot any power
distribution issues that might occur. With
data halls now designed for different
power loads good testing processes
will mean testing beyond the expected
power per square metre to ensure that
there is enough headroom for new
generations of converged hardware.
UPS testing also requires sufficient
load to fully test the ability of the
batteries to provide power to the data
halls and equipment for the required
length of time. A common mistake is
not spreading the load throughout the
facility to ensure that any power loss is
properly factored in to the UPS.
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