Foraging for storage

When Ron Czarnecki, a network administrator with the city of Arvada, Colo.,

began his search for a data-storage solution about 18 months ago, he learned

a simple lesson about storage-area networks (SANs). Money talks.

Czarnecki was seeking an alternative to traditional server-attached

storage that would reduce maintenance headaches and provide a scalable platform

for storage growth. He was anxious to investigate SANs and issued a request

for proposal to Compaq Computer Corp., Dell Computer Corp., XIOtech and

EMC Corp.

"EMC called us to ask how much money we had to spend," Czarnecki recalled.

"We told them about $50,000 to start. They never called back."

In the end, Czarnecki deployed a XIOtech shared storage array described

by the vendor as a "SAN in a box." Although the solution is not a pure SAN

— a network of heterogeneous storage devices and heterogeneous servers — he is pleased with the acquisition, which he believes will solve both present

and future storage requirements for the city.

At his recommendation, the Arvada Police Department recently deployed

two more arrays from the vendor, a Seagate Technology Inc. company. One

array will serve as a disaster-recovery mirror for the original platform

fielded by Czarnecki.

Elsewhere, county and city government IT organizations are having similar

experiences. They are learning an almost mathematical truism: Burgeoning

data-storage requirements plus limited budgets does not equal a SAN. Fortunately,

other storage solutions — including shared arrays, network-attached storage

and homogeneous vendor storage networks — are available to meet their needs.

Doing the Math

According to Joe Butt, senior analyst with Forrester Research Inc.,

Cambridge, Mass., mathematics is at the heart of slow SAN adoption rates

in small to medium-size organizations. He said any organization, regardless

of its size, can expect to pay seven to 10 times the cost of the storage

devices themselves to deploy them in a SAN.

The explanation for high SAN costs, Butt said, is equally simple: SAN

deployments require time, staff and expertise — "all of which may be lacking

in smaller IT shops, such as those of state, county or local governments."

Additionally, the more heterogeneous the infrastructure — the more

diverse the types and brands of servers and storage devices that must be

interconnected in a SAN — the greater the difficulty in getting the current

generation of SAN products to work, Butt noted.

Those difficulties are not unique to government, and they underscore

the problems with SANs.

In general, small organizations might be well served by a small storage

network using products from a single vendor end-to-end. Such SANs, he said,

are often less difficult to deploy and offer some of the scalability and

manageability features that are promised by larger solutions.

"In most cases, however, the organizations having storage problems already

have heterogeneous storage and server environments," Butt said. "They need

a more manageable storage infrastructure, but they are reluctant to deploy

a SAN because of cost [or] interoperability issues, or because they simply

don't have the people to deal with it."

Many of the complexities of current- generation SANs derive from the

use of high-speed Fibre Channel as the link to interconnect servers and

storage devices with switching equipment. The Fibre Channel protocol remains

a mystery to many prospective SAN users, Butt said, and its comparative

youth as a standard contributes to interoperability difficulties among SAN

equipment vendors and deployment headaches for users with heterogeneous

network environments.

IP-Based SANs on the Horizon

Butt foresees a jump in SAN deployments once new storage networking

protocols that use Gigabit Ethernet and TCP/IP networks are introduced to

the market. One such protocol under development by the Internet Engineering

Task Force (IETF) — called iSCSI — enables block-level storage data to move

across traditional IP-based Ethernet networks, making it easier and less

expensive to deploy than Fibre Channel, he said.

This view is shared by Robert Passmore, an analyst with Gartner Inc.,

Stamford, Conn. He said iSCSI-based SANs could leap over Fibre Channel SANs

technologically by providing networks that operate at 10 gigabits/sec before

Fibre Channel could offer comparable capabilities. He noted that iSCSI SANs

are rapidly becoming available, citing IBM Corp.'s new IP Storage 200i

series disk array as an example.

Numerous host bus adapter and storage management vendors, including

Adaptec Inc., are also preparing products for delivering IP-based SANs this

year. In addition, vendors ranging from NetConvergence Inc. to Cisco Systems

Inc. are preparing switching, routing and gateway technologies that will

enable storage traffic to flow across IP networks.

Another key advantage of IP-based SANs will be lower overall networking

costs, according to Lauri Vickers, a senior analyst at Cahners In-Stat Group,

Scottsdale, Ariz. She notes that the cost per switch port to deploy Fibre

Channel is currently about $1,400, compared with about $750 per port for

Gigabit Ethernet. Ethernet switching costs are falling more rapidly than

Fibre Channel costs because of the difference in the numbers of ports installed,

she noted.

Anne Skamarock, senior analyst with Enterprise Management Associates

Inc., is less bullish about the IP-based SAN market. "I have only heard

of a few vendors working on iSCSI SAN products," she said, and those vendors

typically are not targeting enterprise storage requirements. "The IBM solution,

for example, is targeted at small to medium-size organizations. I was kind

of disappointed."

Storage vendors are the first to acknowledge that SANs are still evolving

and will become more accessible with time.

"A couple of years ago, a SAN solution was successful only with people

who absolutely needed a SAN," said Paul Ross, director of network storage

marketing for EMC. "It has only been in the last year that the concept of

SAN has begun going mainstream."

However, new challenges have emerged as a result of the increased popularity

of SANs. "People want to use more complex fabrics, combining many different

storage platforms with many different servers," Ross said. "It is a challenge

to get all of the components of a heterogeneous SAN to work together at

the same time without breaking. Since we own any problem when customers

buy our equipment, we are working to make sure that configurations pass

our quality assurance tests before we approve them."

According to Ross, that philosophy led to the recent announcement by

EMC that the company was qualifying several SAN configurations that would

include storage products from EMC and other vendors. The company is exercising

the same careful testing before releasing IP-based SAN solutions. Although

it continues to offer SANs based on Fibre Channel, EMC is "working hard

with Cisco Systems and the IETF IP Storage Working Group to make sure that

iSCSI becomes a viable interconnect," Ross said.

Jon Pollock, director of storage marketing for Dell, agrees that iSCSI

and other IP-based SAN technologies hold promise, but he questions the view

of some analysts that SANs are too costly to deploy until IP-based SANs

arrive. Dell offers its own SAN — which includes Dell servers, host bus

adapters, switches and storage products — as a plug-and-play SAN solution

that, in Pollock's view, "targets exactly the type of environment that you

find in government" as well as in small to mid-size organizations.

"Dell is a leader in this kind of setting, which requires the sharing

of 250G of storage between two to four servers," he said. "We provide a

completely redundant configuration for less than $50,000. Our solution is

in its fourth generation and is Fibre Channel down to the disk drives."

Healthy Competition

The debate about the cost and manageability of SAN solutions might push

some organizations to consider alternatives.

Competition to entry-level homogeneous SANs comes in the form of shareable

storage arrays from XIOtech, Hitachi Data Systems Corp., EMC and others,

as well as network-attached storage (NAS) platforms from Network Appliance

Inc., Procom Technology Inc. and many others. A NAS device attaches directly

to a general-purpose network, providing servers and clients with direct

access to its data.

Homayoun Yousefi'zadeh, senior product manager for Procom, Irvine, Calif.,

is bullish on network-attached storage. "Today, NAS delivers things that

SAN cannot: support for heterogeneous server operating systems, true data

sharing, a familiar network infrastructure, plug-and-play installation and

others," he said.

Procom is a part of a movement within the industry to add some SAN capabilities

to NAS, such as block-level access to data. NAS currently supports data

access in the form of files rather than discrete blocks as required by some

transaction-processing applications and databases. The result of those efforts,

he said, will be the creation of "a NAS/SAN hybrid that will capture the

benefits of both technologies."

Even before those hybrids arrive, NAS makes "a strong case on a price-performance

basis as a data-management solution that can leverage existing standards

and architectures in storage and networking," said Michael Alvarado, storage

networking marketing manager for Network Appliance.

NAS addresses problems ranging from shortages in employee skills — IP

network-savvy job candidates are more plentiful than Fibre Channel-savvy

types — to the needs of knowledge workers in small to medium-size organizations.

"The storage appliance metaphor has a particular appeal to knowledge workers

who need to share data across networks as a key to business success but

need a storage solution that doesn't require a large IT organization to

deploy or manage," Alvarado said.

"The XIOtech array centralizes our data and allows it to be shared among

the four servers — running [Microsoft Corp.'s Windows] NT, Unix and [Novell

Inc.] NetWare — that are connected to it," he said. "When we need to connect

more servers, we will decide whether to put in a SAN fabric switch or just

deploy another box. If we run short of capacity, we will either change out

disk drives for higher-capacity drives or deploy another box. It is the

easiest way to go — a one-stop shop."

Toigo is an independent consultant and author specializing in business automation

issues. He can be reached via his Web site at www.toigoproductions.com.