number of challenges arise as the amount of digitised
data generated by an organisation increases. Could storage
virtualization be the answer to all these problems?
by Avijit Basu
there's never enough of it. With businesses generating
more and more data, and many islands of data storage
sitting on servers and other secondary media, it is
a nightmare for companies and their IT administrators
to manage stored data effectively and efficiently.
Accessing data can be complicated, using it optimally
is almost impossible, and taking backups can be tricky.
But that's not allthe problems increase considerably
as the amount of data stored goes on ballooning. In
2002 storage is poised for 6 - 18 percent growth, and
this growth will increase to almost 30 percent by 2004.
The question is: Is it still viable for companies to
use the traditional approach of discretely allocating
specific storage devices to different, individual application
Imagine being able to carve out space, expand storage,
link to storage on other devices, and logically move
terabytes of data in seconds with only a few keystrokesall
without bringing the system down. Storage virtualization
allows you to do all this and more in a heterogeneous
server environment. Virtualization in fact, is a pioneering
technology, and it is helping to resolve many critical
Simply put, storage virtualization (SV) is the ability
to utilize all available space in a central data storage
pool, thus allowing data to be centrally managed and
shared across the enterprise. Its purpose is to hide
the complexities of the overall storage infrastructure
of the enterprise from users and IT administrators.
In other words, users no longer need to know where storage
devices are kept, or what their capacity is.
For example, a user may think that his/her computer
has a 100 GB disk attached for storing data, while in
reality, the disk could be anywhere on the company network.
It may not even be a single diskit could be a
cluster of different disks, or a part of different 'types'
of disks including tape, magnetic or optical disks.
To users, it is merely a single, large, attached disk.
To IT administration, it is a standard environment for
application development and a simplified and less expensive
In its purest form, virtualization allows users to add
storage capacity using inexpensive, commodity disk,
tape drives and to dynamically manage those storage
resources as virtual storage pools with little regard
for what physically resides on the back-end.
Virtualization is the trend in the storage networking
market right now, but it is not a new concept. The tools
involved have existed in IT data centres for years.
It pops up in applications, servers, file systems and
volume managers. Storage virtualization is about creating
and managing virtual storage devices by taking blocks
of storage on the individual disk drives and presenting
them as Logical Units of Storage, or LUNs. What system
administrators then see are not the actual physical
disk drives, but rather a simplified 'virtual' view
of the physical storage across disk drives.
The difference between virtualization in the mainframe
arena and virtualization as it exists today is that
earlier it was proprietary where storage solutions from
various vendors evolved within each vendor's favoured
proprietary scheme, and were not necessarily interoperable.
Today's virtualization platform is open.
Different Faces of Virtualization
Storage virtualization can be implemented with different
schemes or standards. At present, many companies are
designing and building solutions according to their
ideas of virtualization. One apparent distinction is
based on the architectural viewpoint, which offers three
types of virtualization: host-based, storage-based and
finally, network-based. Other important vendor distinctions
for virtualization solutions are based on ease of use
Storage is becoming the largest slice of the pie in
the IT manager's product budget chart, accounting for
about 50 percent of total costs. Analyst had predicted
a 30 percent storage growth in India in 2002 alone,
increasing to almost 40 percent by 2004. And while IT
budgets and available personnel are shrinking, the explosive
demand for storage capacity and management remains.
Virtualization allows for a huge amount of growth in
storage, without adding management staff.
Virtualization greatly enhances the capabilities of
storage administrators, whose ability to manage storage
with a comprehensive virtualization tool set significantly
drives down storage administration costs. A storage
virtualization solution eases the task and cost of storage
capacity planning. It allows usage of heterogeneous
storage, empowering enterprises to leverage their current
infrastructure and to make future purchases based on
the best choices available rather than being tied to
homogeneous proprietary storage offerings.
Virtualization enables implementation of enterprise-wide
storage management. It can provide enterprise-wide manageability,
allowing storage systems to be constantly available
and scalable to meet future needs. It allows easy storage
space reallocation with minimal impact to application
servers, diminishing downtime and allowing enterprises
to do business at optimum intensity, round-the-clock.
Virtualization is also fundamental in enabling business
continuity functionality such as mirroring and remote
Virtualization will enable any end-user anywhere to
access and share any file regardless of the storage
system used by them, the network, the operating system
or applications, or the overall security of the system.
In terms of virtualization trends, many storage experts
are of the opinion that the current period of budget
tightening and the advent of the virtualization sub
market will strain market growth of proprietary storage
vendors, and there could be a shift in the leader board.
Some also see integration and consolidation of network
attached storage (NAS) with storage area networks (SANs).
There will be an increased focus on infrastructure,
and more focus on integrating different servers, network
attached infrastructures, and storage area network infrastructures.
So, people can basically validate that the different
technologies they're incorporating will work within
an infrastructure. There will be a rapid pace of technological
investment with more and more vendors trying to help
customers protect their technology investments. Enterprises
are no longer willing to pay large premiums for products,
only to find them obsolete in 12-18 months. To enable
that rapid evolution of technology, different vendors
and different system vendors will begin to support upgrades
and investment protection.
In terms of growth, it is going to be unprecedented.
Soon, 85 to 90 percent of enterprises will be using
some form of virtualized storage to take full advantage
of the SAN technology. According to Gartner, the SAN
market will grow to $40.40 billion in 2004. In fact,
to sum it up, storage virtualization could be the 'killer
application' of networked storage, and in the coming
years, become a crucial factor in driving a company's
choice of storage vendor.
The writer is Marketing Manager (NSSO),
Business Customer Sales Organization, Hewlett-Packard