As a response to the current economic climate many

As a response to the current
economic climate many
organisations are turning to IT
consolidation in an effort to cut
costs, with virtualisation as one
of the fundamental technologies
underpinning these projects.
Mark Lewis, EMEA Marketing
Director at Riverbed Technology
considers two major problems
which can be encountered in
a virtualised environment.
Setting up a consolidated infrastructure
based on virtualisation simplifies
administrative efforts and improves
resource utilisation and data protection.
Nevertheless, for organisations
with distributed staff and a wide
area network (WAN), virtualisation
remains a real challenge.
When consolidating an information
system, IT managers must consider
application performance and data
availability. Care must be taken
not to resolve one problem while
creating others, since the investment
necessary for damage repair might
cost more than any savings made.
Application performance
The first challenge revolves around
application performance. The rise of
the decentralised computing model
was largely driven by the need to keep
IT resources closer to the distributed
user base to achieve the best possible
performance. Consolidating servers
from remote sites reverses this
distribution and, consequently, many
applications suffer severe performance
degradation after consolidation.
To remedy these performance problems,
organisations often look to upgrade
bandwidth in an effort to improve
application response times. Instead, CIOs
often discover that upgrading bandwidth
to remote sites has little or no effect on
application performance, because the
performance problem lies with latency
and application protocol inefficiencies
across the WAN. In addition, the cost of
bandwidth upgrades can often offset a
significant portion of any cost savings
achieved from IT consolidation.
IT consolidation
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Data and system availability
The second consideration is the increased
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data management
reliance on all the centralised IT assets.
Because the infrastructure is serving
more users per physical piece of
hardware, the requirements for system
and data availability go up dramatically.
In addition, site consolidations limit the
geographical diversity of IT operations
and subject businesses to the risk of
a site or regional outage. While server
virtualisation can help greatly reduce
the amount of time required to redeploy
servers in the event of a failure, it does
not necessarily protect against site
failures or data loss or corruption.
Therefore, building a comprehensive
disaster recovery and business
continuity strategy has become critical
for enterprises adopting a consolidated
infrastructure. Consequently, IT
departments are increasingly turning
to technologies such as data replication
and continuous data protection (CDP) to
remote sites along with virtual tape library
(VTL) for disk-to-disk backup operations.
Points for consideration
For most organisations, IT infrastructure
consolidation presents a major opportunity
to cut costs, but the degradation in
application performance creates a
significant trade-off that can result in
some applications becoming unusable
over the WAN. In these scenarios,
organisations must decide to either forego
consolidation efforts or run the risk of
crippling the end-user experience. In
some cases, companies have embarked
on a consolidation project only to have it
come to a halt due to the adverse impact
on business applications and end-users.
Organisations seeking to fully realise
the benefits of consolidation must
ensure real-time access to applications
and data for their end-users. WAN
optimisation solutions help businesses
who have centralised their computing
environment address this problem
by delivering LAN-like performance
for applications over the WAN.
WAN optimisation enables LAN-like access
to virtualised infrastructure for users
regardless of location. It accelerates the
performance of all transmission control
protocol (TCP) applications running over
the WAN by addressing the three primary
issues, namely bandwidth constraints,
TCP latency and application chattiness.
WAN optimisation overcomes
performance issues in four ways:
• R
educing the volume of data sent
and freeing up bandwidth by
eliminating redundant data;
• Reducing TCP latency and chattiness
by decreasing the number of
roundtrips required to transmit data;
• Accelerating strategic applications by
using specific optimisation modules;
• Simplifying control and management
by automating provisioning tasks and
providing advanced reporting tools.
The ultimate goal is to provide users
with fast and secure access to their
data and applications through the
virtualised infrastructure regardless
of where they are based in relation to
the data centre. Thus, access to the
most ‘common’ applications will be
optimised: file sharing, email, content
management systems for collaborative
workspaces, web applications, design
documents, product lifecycle management
solutions and ERP applications.
WAN optimisation is also often a
requirement for a successful disaster
recovery plan. WAN optimisation
shortens backup and replication
windows and maximises the available
bandwidth between the sites, while
at the same time avoiding congestion
with other application traffic.
Conclusion
Infrastructure virtualisation and
consolidation can offer significant
advantages both for IT services and
enterprise operations. Although the
advantages are obvious, enterprises
should always consider the specific
requirements of their operations in
terms of performance and availability.
A combination of WAN optimisation
solutions and virtualisation offers
IT managers a unique opportunity
to facilitate their IT operations in a
strategic manner and improve service
delivery while also saving money.
IT managers would be well advised
to consider these two technologies
as key in their IT infrastructure.
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