By Charles Clark
Network World, 09/24/01
While a buzz has indeed developed around IP storage networking during the
past year, it's not from development of any new technology but rather the
melding of a few existing ones: storage-area networks, Gigabit Ethernet and
TCP/IP.
When first introduced about four years ago, SANs promised to lower the total
cost of ownership and improve availability of storage devices while meeting
the massive demands generated by multimedia applications and 24-7 e-businesses.
However, Fibre Channel, the enabling network technology for SANs, failed to
meet expectations in areas such as affordability, ease of installation, ease
of use and interoperability. These problems led to a slow adoption rate for
SANs and limited market penetration.
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The emergence of Gigabit Ethernet got vendors thinking about using it and
TCP/IP as SAN enablers. That would let users take advantage of their experience
with existing IP and Ethernet infrastructures, meaning they would require
no special training, as was often the case with Fibre Channel. Gigabit Ethernet
hardware is also much less expensive than Fibre Channel.
With all these advantages, it would seem that IP storage networking would
be a slam-dunk as far as acceptance is concerned. But the ball is still a
distance from the rim.
"We just have a couple of products out there in the marketplace and
they should not be considered open products because there is no demonstrated
interoperability," says Nick Allen, vice president of storage research
at Gartner. "We don't even have a standard yet."
The absence of a standard isn't from a lack of possibilities.
At present, vendors offer IP storage networking in three flavors: iSCSI;
Fibre Channel over IP; and Internet Fibre Channel Protocol (IFCP).
ISCSI lets users build SANs using native TCP/IP running over Gigabit Ethernet
LANs, instead of Fibre Channel. Cisco, CNT, Nishan Systems, SANcastle, Pirus,
FalconStor, 3Ware and IBM offer products that use this protocol.
Fibre Channel over IP lets users connect geographically dispersed Fibre Channel
SANs via an IP network, such as for back-up and disaster recovery applications.
CNT, SAN Valley and Lucent support Fibre Channel over IP.
IFCP also connects Fibre Channel SANs to IP nets,
but is typically used only on LANs. It was developed by Nishan,
which uses it in one of its products and has submitted it to the
Internet Engineering Task Force (IETF) for consideration as a
Fibre Channel-to-IP SAN standard. It is likely the IETF will choose
between IFCP and Fibre Channel over IP for its final standard,
perhaps taking features of both.
Progress is being made on the standards front. The IETF is well
along in the ratification process, with final standards expected
late this year or early 2002. In the meantime, vendors are also
at work on interoperability. In July, some 60 vendors attended
Plugfest, sponsored by the Storage Networking Industry Association
(SNIA) and the University of
New Hampshire to uncover interoperability issues.
Besides a standard, other pieces also are missing.
These include host bus adapters, for connecting servers to the
SAN, and accelerators, which are cards that relieve host bus adapters
of processing TCP/IP commands (see "Storage
on steroids"). Several vendors have these products in
beta test.
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Tales from early adopters
Some users can't wait for the standards work to be complete. James Dyches,
director of computer operations at Bell Microproducts, a computer reseller
and systems integrator in Montgomery, Ala., uses FalconStor's IPStor for his
company's primary data center. IPStor is a software-based SAN that works with
a user's existing hardware, including storage arrays, servers and switches.
Dyches started testing the iSCSI-based system in February 2001 and shifted
to production mode in August. He says the product has worked well, offering
near wire-speed performance. But he cautions that, as one of FalconStor's
earliest customers, he received a lot of attention from the firm. Additionally,
Bell is itself a systems integrator with Fibre Channel SAN experience.
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Questions to ask IP SAN vendors
Do you have customers
who are using your product in a production environment?
If so, how many? Can I speak to them?
Have you tested your product for interoperability with other networking storage products? If so, with how many has it been certified as interoperable?
Have you established alliances with any of the major SAN vendors such as EMC, IBM, Compaq, Hewlett-Packard or Hitachi?
How do you plan to make your product standards-compliant?
How does your product compare with Fibre Channel in terms of transport speed?
Will my employees need special training to use your product?
Will I have to make any changes to my networking infrastructure to deploy your product?
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Min Christopherson, director of IT services at DNA Sciences in Fremont, Calif.,
jumped into IP storage networking even earlier than Dyches. In August 2000,
DNA Sciences became a beta-test site for the Nishan IPS 3000 and 2000 using
IFCP.
The major benefits Christopherson gained from the Nishan products are ease
of installation, simplified management, and the ability to integrate SANs
and LANs, he says. Administrators already familiar with Ethernet and TCP/IP
could implement the technology in a couple of days with only the help of the
product manual, as opposed to spending days in training to learn Fibre Channel.
Over time, he expects management of IP SANs will become even easier as it
is integrated with network management, using platforms such as Hewlett-Packard's
OpenView.
Hossein Shahrokhi is another member of the IP Storage early adopter club.
Shahrokhi, executive director of IT services at the University of Houston,
became interested in IP SANs about a year ago as a way of consolidating storage
at the university and providing a nondisruptive back-up system. He rejected
the idea of installing a Fibre Channel SAN because of the high costs associated
with its hardware, the new network infrastructure required and ongoing management.
In August 2000, Shahrokhi says he could not find
a vendor to sell him an IP SAN. Finally, in May 2001, he convinced
Cisco, Compaq and a local systems integrator, LeTigre Computer
of Houston, to take on the project. Cisco will supply its SN 5420
router and iSCSI software, Compaq will supply the storage arrays
and host bus adapters, and LeTigre will handle the integration.
He says he hopes to deploy the IP SAN in a production environment
in early October.
Shahrokhi says he's learned that IP SANs are not for everyone. They are ideal
for organizations that access up to 500 gigabytes of data per day, but not
for those that require tens of terabytes per day. "These types of institutions
will continue to require traditional Fibre Channel SANs, at least until there
is a better technology available," Shahrokhi says.
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IP SAN prognosis
While IP storage is based on the known technologies of Gigabit Ethernet and
TCP/IP, because these technologies are being applied in a complex environment
- storage networking - vendors are naturally still working out
the bugs.
SNIA's Plugfest was a step in the right direction, but many more
will be needed before interoperability can be declared. The upshot
is that IP storage technology really won't be ready for mass adoption
for nine months to two years, analysts say.
Clark is a freelance writer. He can be reached at Cclark1038@msn.com
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