In an effort to continue to improve business productivity and customer
service, most organizations are deploying data intensive enterprise applications
like customer relationship management (CRM), enterprise resource planning (ERP),
and e-mail. This has resulted in an explosion of information and data that has
become the lifeblood of these organizations, greatly elevating the importance of
a sound storage strategy. Selecting a unified architecture that integrates the
appropriate technologies to meet user requirements across a range of
applications is central to ensuring storage support for mission critical
applications. Matching technologies to user demands allows for an optimized
storage architecture, providing the best use of capital and IT resources.
Storage area networks (SAN) have emerged as the best solution for advanced
storage requirements. Often, SANs can alleviate many if not all of the pain
points of IT managers, since they allow for more manageable, scalable, and
efficient deployment of mission-critical data. Not only do SANs provide advanced
functionality, but they also lower an organization’s total cost of ownership (TCO)
and provide significant positive return on investment (RoI) versus a direct
attached storage (DAS) environment.
Not all SAN technologies are the same. However, in order to realize the
positive benefits of SAN deployment, the choice of vendor and SAN implementation
partner is just as critical as the SAN equipment itself. Centralized, efficient
management, intelligent SAN services, a truly robust and flexible platform and
global, 24×7 service and support are requisites for next-generation SAN
technologies. Any solution that closes off heterogeneous options-whether it is
protocol-, vendor-, or equipment-specific-will only be a transient solution
with limited strategic and RoI justification. The optimal SAN solution will have
a robust, high-performance architecture that creates new opportunities and
alternatives while protecting resource investments from unexpected turns in the
economic environment and changes in market adoption of new technology.
An IT Manager’s Dilemma
IT managers across three states in the US identified the following five
major ‘pain points’ when asked about their storage management.
–Â Difficulty of managing large, disparate
islands of storage from multiple physical and virtual locations.
–Â Complexity of maintaining scheduled backups for multiple
systems and difficulty in preparing for unscheduled system outages.
–Â Inability to share storage resources and achieve efficient
levels of subsystem utilization.
–Â Shortage of qualified storage professionals to manage storage
–Â Confusion over the justification of a plethora of storage
technology alternatives, including appropriate deployment of fiber channel,
Internet small computer systems interface (iSCSI), fibre channel over IP (FCIP),
and InfiniBand. To add to these technical dilemmas, IT managers are facing
restricted budgets and increasing costs of deploying and maintaining both DAS
and SANs, despite decreasing prices for physical storage in terms of average
street price (ASP) per terabyte. The result, that IT projects are faced with a
greater of scrutiny than ever before.
However, regardless of the economic environment and the
abundance of new technologies, organizations must continue to invest in IT
projects that support specific business goals and that can produce quick RoIs. A
well-planned, well-justified storage strategy will allow a business to emerge
from adverse market conditions in a better position to take advantage of new
opportunities. In effect, the choice of storage investment can actually result
in a sustainable competitive advantage versus the competition. For example, a
brokerage firm that loses the ability to commit transactions during trading
hours will suffer significant losses relative to a competitor.
A large consumer goods retailer that can’t determine its
inventory in real time because of insufficient storage will suffer higher costs
than a competitor that has implemented storage provisioning and management tools
that can track inventory flows and store all relevant data in an easy-to-access
It is important, therefore, that the decision makers in the
storage strategy include not only technical IT managers, but also business and
financial managers who want a greater strategic and financial justification in
order to invest the organization’s capital.
Evolution and Benefits of Networked Storage
The evolution of SAN has progressed to the point where all organizations
should seriously evaluate their role in the future of their storage environment.
According to a recent report from Gartner Dataquest, the market for SAN-attached
external storage in 2005 will exceed $22 billion, representing almost three
million terabytes of data.
The main reason SANs have emerged as the leading advanced
storage option is because they often can alleviate many if not all of the pain
points of IT managers. They allow for more manageable, scalable, and efficient
deployment of mission-critical data.
A large number of enterprises have already tested or
implemented production SANs and many industry analysts have researched the
actual benefits of these implementations. A study of large enterprise data
center managers by Gartner andWitSoundview shows that 64 percent of those
surveyed were either running or deploying SANs. Another study by the Aberdeen
Group cites that nearly 60 percent of organizations that have a SAN installed
have two or more separate SANs. The study also states that 80 percent of those
surveyed felt that they had satisfactorily achieved their main goals for
implementing a SAN. Across the board, all vendor case studies and all industry
analyst investigations have found the following benefits of SAN implementation
when compared to a DAS environment: ease of management, increased sub-system
utilization, reduction in backup expense, and lower TCO.
Business Impact of Current SANs
IT managers perceive the benefits of a centralized point of management since
it makes the everyday work of storage administrators easier. But, to truly
justify a SAN investment from both a technical and a business perspective, it is
necessary to attach concrete savings in money terms to the benefit or to define
a concrete source of competitive advantage. While the hard cost savings are
usually enough to justify migrating to a SAN, the less-easily quantifiable ‘soft
benefits’ may provide the most compelling argument.
A good IT investment (and, therefore, a good networked
storage architecture) should lead to a lower TCO and a higher RoI. In this
paper, TCO refers to the full cost of a project including upfront capital costs
and recurring costs over the period of the project (two years, three years,
etc.), and RoI is the average expected cash flow over the period of the project
divided by the initial investment outlay.
There are three major quantifiable savings associated with
SANs that lower TCO and result in a large positive RoI versus DAS environment:
reduced management costs, reduced sub-system costs, and reduced backup costs.
There are also two more strategic benefits of SANs that, though difficult to
quantify, may be even more important justifications for SAN implementation: high
availability and disaster recovery.
A study by McKinsey and Merrill Lynch shows that the TCO of SAN solutions
typically is less than half that of DAS solutions primarily because of huge
savings in management costs. The study found that SANs were able to lower the
budget for storage administrators from 47 percent of total cost to less than 10
The main reason for the cost savings is that SANs are easier
to manage than DAS because of the existence of a simplified, central point of
control for monitoring, backup, replication, and provisioning. This results in
an increased amount of TB of data that a single storage administrator can
manage. This frees up time for administrators to devote to more value-added
activities. This time saving results in slower staff growth and ultimately
decreases the required rate of hiring.
SANs allow any-to-any access and connectivity between storage and servers.
Therefore, servers can be better matched with underutilized sub-systems and
overall capacity utilization can increase. This leads to savings on future
sub-system purchases as less disks need to be added each year. For example, in
DAS environments it is usually possible to achieve 50 percent capacity
utilization of usable data storage space. So, if an organization has 20 TB of
data to store, it will actually have to purchase 40 TB of disk. Current SANs can
increase utilization to about 70—85 percent. The same organization would only
need 24—29 TB of disk in this scenario. The difference in storage utilization
can add up quickly in a fast-growing organization.
Compared to physically separated SANs, VSANs (virtual SANs) offer much
greater flexibility. Moving a device from one VSAN to another requires only
configuration at the port level, rather than a physical move. Compared to
zoning, VSANs provide a more complete mechanism for traffic isolation by
enforcing control of frames at every step along the way, rather than only at the
edge of the fabric.
This partitioning of fabric services greatly reduces network
instability by containing fabric reconfigurations and error conditions within an
individual VSAN. Should a fabric function such as fabric shortest path first (FSPF)
have a failure, the failure is contained to the VSAN and has no effect on the
rest of the switch. VSANs also provide the same isolation between individual
VSANs as would exist between physically separated SANs. Traffic cannot cross
VSAN boundaries and devices may not reside in more than one VSAN. This attribute
of VSANs is of great value in service provider environments where absolute
separation must be maintained between customers. Since VSANs each run separate
instances of fabric services, each VSAN has its own zone server, name server,
and FSPF and can be zoned in exactly the same way in which SANs without VSAN
capability are zoned.
VSANs save customers money by enabling them to consolidate
physically separate switch infrastructures that may not have optimal port
utilization into one physical infrastructure that can be managed as a single
logical entity. Not only is this one infrastructure easier to manage, but in
general it will have fewer ports.
Excerpted from a Cisco white paper
Source : Voice&Data