Server virtualisation is
a technology that not only saves money but results in a more agile
business, argues Simon Gay, consultancy practice leader at Computacenter
ICT departments are under
constant pressure to reduce costs and perhaps there is no single
area receiving more attention than the ever increasing quantity
of Intel servers. All too frequently, a single server supports
no more than a single application and many have been deployed by
end-user departments away from the control of the central ICT function.
In many cases, the servers are poorly managed and disorganised,
with inadequate documentation and limited understanding of the
build of each machine.
It’s time to adopt a more innovative approach
to deploying and managing these servers. This requires a shift
in thinking, away from seeing the ‘server’ as a physical
entity – where one box is the mail server, another is the
web server and so on — towards regarding the servers in terms
of the work they do and the services they provide. This change
in approach leads almost inevitably to virtualisation, where multiple,
software-based servers are logically stored on a single machine.
This not only addresses some of the problems ICT managers face,
it introduces a number of benefits that offer significant opportunities
for a business to increase its agility and responsiveness.
Rethinking resources
One of the most immediately compelling reasons for such
a rethink is simply the resources that are consumed by physical
servers. Very few servers are in constant demand, and even those
that appear to bear heavy loads and seem to be in use continually
are, in fact, often sitting idle. Even if a web server serves up
a page every second, it may take only a fraction of a second to
do that. So the machine’s processor is still doing nothing
for much of the time. Other applications — for example, payroll
or billing systems — may have long spells of inactivity or
light use interrupted by bursts of activity. Overall, a physical
server will usually show percentage of CPU usage in single digits.
Worse still, there may be applications that are entirely redundant.
And there may be others that are run just every now and then. A
recent survey in one organisation showed that fewer than half of
its 3,000 applications were actively in use.
Aside from the considerable hardware purchase cost, you have
to house and maintain these machines. This is made significantly
harder if many of them are scattered around the organisation. No
wonder that the servers are rarely properly documented.
If we assume that these applications are important or even critical
to your business, the problem is immediately doubled by the requirement
for disaster recovery capabilities. The standard approach to disaster
recovery is to replicate the production systems, which means a
large amount of hardware sitting around doing nothing. With poor
documentation of the live systems, your chances of getting a backup
system up and running efficiently and accurately, with no loss
of data or business, is greatly reduced. Virtualisation, by its
very nature, incorporates many of the proven advantages of server
consolidation. Centralisation of the facilities makes management,
backup and recovery easier and more cost-effective. These benefits
are further enhanced by the lower hardware overheads which also
translate into reduced management and maintenance costs.
Flexible infrastructure
Recent research shows that developing efficient/flexible
infrastructure is a primary aim for CIOs and virtualisation is
a key step along this path.
The process of setting up a virtual server involves creating a
configuration file. You can store that configuration until it’s
needed, at which point you can recreate the server in very little
time. That’s why disaster recovery is so much easier.
It’s also much more flexible because you can decide, at the
time of recovery, which servers to recreate, and change your mind
later if you like, with minimum disruption and maximum utilisation
of the available hardware capabilities. This hugely reduces the
requirement for the business to predict what it would need under
such circumstances.
But that flexibility isn’t confined to fighting problems.
With virtualisation, you’re able to clone existing servers,
and make the applications they run available as a standard, pre-packaged
system that you can roll out in a timely manner. For one customer,
Computacenter reduced the deployment of certain key applications
from weeks down to days. You don’t have to wait for hardware,
you don’t have to have someone physically assemble it, install
the operating system, apply the patches and install the application.
With virtualisation, it’s already there, ready to run using
the existing resources.
This gives an organisation unprecedented agility. You can react
very quickly and effectively to changes in your business — such
as opening a new branch, launching a new product, or responding
to market changes. It also means you can set up development, prototype
and proof-of-concept systems without either impacting your live
production systems or investing huge amounts in computing capacity
that will be redundant once the development activity ends. Virtualisation
makes it cost-effective to create systems that will be needed for
just a few weeks or months.
Similar advantages apply to live systems. By matching applications
of complementary characteristics and running them on the same hardware,
you can make the best use use of those resources — for example
by marrying those resources that run heavily at night with those
that run heavily during the day.
Unexpected demand
Furthermore, one of the reasons that physical servers are
often so inefficient is that they must have spare capacity to deal
with unexpected demand. With virtual servers, which share the available
resources, you can fine-tune each server as needed. If your web
site suddenly starts getting more hits than you expected, or a
rush of orders means your order processing system is under heavy
load, you simply reassign resources appropriately, in next-to-no
time. All the time you ensure that you are making the maximum possible
use of your computing resources.
Virtualisation systems have matured greatly over the past couple
of years. But the real innovation here is not in the technology
but in how you think about the way you use servers. Rather than
being a necessary burden, virtualisation enables the server to
become a valuable strategic tool in enhancing the agility and competitiveness
of the business. |
