Storage area networks find room to grow
Garry Kranz
05.04.2001
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Networked storage
Storage area networks find room to grow
The information age presents network managers with a daunting challenge:
store ever-increasing amounts of business-critical data, keep it secure
but accessible at high speeds to multiple users, and ensure timely,
regular backup -- all without increasing IT costs. Some companies see
storage area networks as a solution.
by Garry Kranz
As companies grapple to store and protect vaster amounts of data,
storage area networks (SAN) are gaining momentum. A SAN is a dedicated
configuration of multiple servers connected to peripheral storage
devices using high-speed fiber and special routers, switches and hubs. A
SAN, usually part of an enterprise's overall computing resources,
enables enterprises to consolidate data from disparate servers on to a
centrally managed storage network.
Storage area networks offer certain key advantages over file serving and
network-attached storage (NAS) boxes, namely improved data sharing,
convenient storage expansion, remote backup and recovery and increased
uptime.
But the adoption rate of SANs has been slowed by drawbacks such as high
cost, interoperability of software, hardware and components and data
security concerns.
The Pros
Data Sharing.
A SAN makes stored data available to multiple users simultaneously,
without disrupting productivity. "A SAN provides high-speed access to
data among a number of system servers, thus enabling data to be
retrieved faster when used by a large number of users," says Dave
Howard, chief executive officer at 1Vision Software Inc. in Loveland,
Colo. "This is critical for efficient company operations and for Web
storage where millions of users may need to access data."
Individual computers in a SAN see each data-storage device as a shared
resource, eliminating data bottlenecks common to NAS and file serving
environments. "You might have 20 computers, but each one sees the
storage as one big pool," says Fabrice Helliker, a London-based vice
president of engineering for BakBone Software, headquartered in San
Diego, Calif.
Live expansion capacity.
A SAN allows network administrators to expand storage capacity without
shutting down critical file servers. Instead, new storage devices are
plugged directly into the fiber connecting the various servers to
existing storage capacity.
"With the Internet, system administrators have to make sure their data
is available all the time -- and keep it safe to boot," says Christopher
Poelker, a storage architect with Hitachi Data Systems in New York City.
Remote backup and recovery.
Since it's a separate network, a SAN enables automatic data backup,
meaning IT administrators don't need to swap out backup tapes each day.
Backup occurs without interrupting users on other company computer
networks. "One of the complaints of companies [using NAS boxes] is that
backup traffic is consuming too much bandwidth from their production
networks," says Lee Abrahamson, manager of SAN consulting for storage
networking specialist CNT in Minneapolis, Minn.
A SAN also makes data migration more manageable. Data is transported
across a high-speed fiber and stored on a remote server. "This
eliminates the need to store data on the hard drive of individual
machines," says Jim Rodriguez, senior security consultant with
Atlanta-based Crescendo Technologies. It also makes data recovery easier
if there's a disaster.
The Cons
Cost.
Industry experts say a comprehensive SAN could cost hundreds of
thousands of dollars, putting them beyond the reach of most small
enterprises. Although a SAN could yield savings through the need for
fewer IT professionals, the upfront cost intimidates most companies.
Some small and medium-size enterprises might want to build miniature
SANs, consisting of a few switches on the network, for specific
departments and applications. These smaller networks give you a head
start and can be expanded later to accommodate your computing needs.
Interoperability.
Interoperability also is a drawback. Companies implementing a SAN often
buy hardware from one company, software from another company, while a
third company supplies the components needed to connect everything
together. "There is no overarching standard for SANs right now," notes
Howard. "A lot of vendors make a single component, so companies need to
be careful that the components they select are compatible with their
system."
The Storage Networking Industry Association of Mountain View, Calif., is
promoting open standards to ensure that different vendors' storage
networking product products work compatibly. But the association
concedes open standards are at least a year or two away.
Network security.
The lack of industry standards also heightens concern about security and
the ability to prevent unauthorized access to data. Several workable
options exist, including hybrid systems that use newer technology with
more established architectures. Enterprise Storage Group of Milford,
Mass., claims that concern about security is the chief impediment to
widespread implementation of SANs.
Security safeguards should be built into a SAN, says Bill Van Emburg,
chairman of Piscataway, N.J.-based systems integrator Quadrix Solutions
Inc. "A SAN really is no different than any other computer network. The
same need to separate different kinds of machines so that they can't be
used to leverage each other's access still exists," says Van Emburg.
Who's Using SANs?
Despite the economies of scale they offer, cost and technical complexity
have kept adoption rates of SANs low. It is estimated only 5-10 percent
of Fortune 500 companies have installed SANs. The rate among smaller and
medium-size enterprises is much lower. In a few years, however, SANs
could become a necessity for all organizations with growing data storage
demands, especially given the projected growth of e-commerce. "Before
SANs, the choice was to add more storage capacity to a single server,"
says David Hill, a storage analyst with Boston-based Aberdeen Group.
"But no longer it is enough to throw more space at a storage problem.
The key is to manage space more effectively, because the one thing
companies can't afford to be is: down."
Garry Kranz is a freelance business and technology
writer based in Richmond, Va.
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