The subject of virtualization evokes a variety of reactions when
put forth to a CIO. Given that the term indicates different things
to different people and since companies are in varied stages of
adopting this technology, CIOs are keen to demystify this
technology.
Virtualization must be seen as a concept and an enabling
architecture rather than any single piece of hardware or software.
Questions like: “So you think I can introduce virtualization
into my data center by installing this piece of code?” or
“Can your new server ensure that our IT environment is
virtualized and give us the cost savings promised?” must be
replaced with queries such as:
- “Which type of virtualization do you think our
organization is best suited for?”
- “If we want to use virtualization for our ERP
application, would it bring the same level of savings as a server
consolidation exercise?”
To make this move towards more focused and results-oriented
questions, it is imperative to understand different aspects of
virtualization and how it can bring real-world benefits to an
organization.
By introducing a layer of abstraction between hardware and OS
and applications, virtualization helps IT administrators manage all
the complexity of multiple software and devices in a much easier,
speedier and cost-effective form.
There are three main areas of computing where virtualization is
making the most headway and impact:
- Server virtualization: In server
virtualization, the different server resources—including
physical identity of the machines, OS and types of
processors—are masked with the goal of enabling the server
users or administrators to maintain, upgrade and manage the servers
without going into the complicated details of each of those
resources.
- Storage virtualization: Storage virtualization
means pooling together of different types of storage devices into a
single ‘storage system’ (commonly achieved through SANs
or storage area networks) so that the entire usage and management
of company-wide or data center-wide storage can be done through a
simplified single console. The servers connected to the storage
system are not aware of where the data really is.
- Network virtualization: In network
virtualization, the available bandwidth is ‘carved up’
into different channels and can be used for multiple
purposes—components of a virtual network could include
NIC’s, switches, VLANs, network storage devices, virtual
network containers and network media. Each channel is independent
of others and can be assigned to any server or computing device in
real time.
The idea of virtualization in any of the three domains is to
simplify the manageability of resources, improve their utilization
and save costs while scaling up or expanding the resources.
Additionally, one could also have application
virtualization where an application runs on another host
from where it is installed in a variety of ways—through
application streaming, desktop virtualization etc. Microsoft
Softgrid is an example of application virtualization.