SAN Strategies

When the storage industry starts to buzz about a new technology, the ears of NT managers naturally perk up. This is the case with Storage Area Networks (SANs), which are generating a marketing furor.

The problem is that SANs -- for most applications, anyway -- are not yet ready for prime time. Industry standards are not fully developed, and switches, in particular, continue to have interoperability problems with products from other vendors. Server vendors who have moved into storage are selling one type of SAN that maximizes their server sales, while pure storage vendors are heading in a different direction.

"At the moment the premise is good, but the promise has not been realized," says David Hill, senior storage analyst at Aberdeen Group ( "In another three to four years the SAN industry will have worked through its interoperability and SAN management issues and be ready to offer true heterogeneous SANs, which at that point will act as an enterprise storage utility," he adds.

For now, SAN hardware -- including servers, tape drives and RAID devices -- is fairly standard. But SAN fabric products, such as switches and hubs, and SAN software and applications are still developing. This makes anything but a homogeneous SAN an exercise in incompatibility.

Despite compatibility issues, sites with certain storage requirements can benefit from today’s SAN technology. NT enterprises anticipating future storage needs should be interested in what SANs will offer a few years from now.

Understanding SANs

SANs are separate enterprise networks, distinct from a LAN or WAN, in which one or more storage devices connect to servers throughout the organization. The pipeline for SAN technology is typically Fibre Channel, which offers high performance and better scalability than is available through SCSI-connected storage devices.

Storage devices that are linked together using a Fibre Channel pipeline provide high availability and failover functionality. They act as a unified resource, balancing loads throughout the available storage capacity, and doling out storage and retrieval jobs using controllers and software.

SAN proponents say the technology helps enterprises counter the "server sprawl" often present at enterprise NT sites. SANs consolidate server resources and manage them centrally. When properly implemented, SANs can eliminate significant volumes of processing activity from the LAN and WAN, reducing network traffic and improving throughput.

At Nahan Printing, a St. Cloud, Minn., direct mail printer, implementing a XIOtech Corp. ( SAN last year resulted in a sixfold to tenfold increase in throughput, says Lyle Myers, system coordinator at Nahan Printing. The company, which routinely moves large graphic and database files from two independent applications, used the XIOtech Magnitude SAN to combine SCSI storage devices into one Fibre Channel-based SAN with a capacity of 300 GB.

The Fibre Channel pipeline can connect storage devices at distances as great as 10 km. Unlike SCSI, Fibre Channel can link unlimited numbers of devices and maintain its performance levels, making SANs scalable for networks with expanding storage requirements.

"It’s a huge opportunity for NT sites in particular, because applications in the NT marketplace are quickly rising to mission-critical stature," says Doug Fiero, manager of network solutions at EMC Corp. ( Using SAN technology helps NT sites with multiple servers to deliver the connectivity required for enterprise-class storage, he adds.

Myers of Nahan Printing is pleased with his XIOtech SAN, citing 100 percent uptime since the implementation. The company will run out of storage space around October 1, so Nahan plans to implement another 300 GB cabinet soon to meet growing demand for storage.

For NT sites, with their hallmark heterogeneous environment, SAN technology has one glaring problem: a lack of interoperability among SAN vendors. Numerous alliances have been formed among SAN vendors, but not one has the critical mass necessary to dictate a true standard.

Some vendors offer limited interoperability, and others claim true heterogeneity. But true interoperability is pretty rare, says Steve Rigney, a senior network analyst at the consulting firm NetReference Inc. ( NT sites with a justifiable need for a SAN, therefore, typically buy from a systems vendor that sells hardware, software and services. And for many sites the strategy works -- for now.

A Swarm of Vendors

Some confusion about SANs has arisen as a result of the large number of vendors that recognize the market potential of the technology. Each vendor has a SAN strategy -- some published and some de facto -- that mark its place in the market.

For server-centric vendors -- such as Compaq Computer Corp., Dell Corp., Hewlett-Packard Co., IBM Corp. and Sun Microsystems Inc. -- the SAN strategy is to sell the most possible units, placing SAN intelligence in the server. Storage-centric vendors -- such as Storage Technology Corp. (StorageTek), EMC, Exabyte Corp. and MTI Corp. -- locate the SAN intelligence in the storage devices or storage software.

A few SAN-specific hardware vendors have popped up or have been reborn from other storage vendors, including Data General Corp.’s Clariion Storage Division, Hitachi Data Systems, XIOtech and nStor Corporation Inc. In addition, a limited number of SAN software companies, such as Transoft Networks -- which was recently acquired by HP -- and SAN fabric vendors, such as Brocade Communications, are building momentum in the market. Even storage vendors without a direct link to SAN, such as Advanced Digital Information Corp. (ADIC) and RAID vendor Mylex Corp., are playing the SAN marketing game.

When The Motley Fool (, a personal finance education company, began to investigate SAN technology, Dwight Gibbs, the company’s chief technology officer, who’s official tittle is Chief Techie Geek, made choices knowing about the problems caused by the immaturity of the market. "Fibre Channel is very new and there is no doubt that interoperability is a tricky issue. We wanted to maintain as few vendors as possible," he explains. Already a Compaq NT shop, The Motley Fool opted to bring in a Compaq SAN.

With 100 GB of data and growing, the company wanted a solution that could provide failover and high performance. While picking the best component and building a complete SAN solution was appealing, Gibbs realized that management costs would outweigh whatever savings he could generate from a best of breed approach.

In this market, "I’d rather go to one vendor and say, ‘put your support where your mouth is,’" Gibbs says. Being down is not an option. "I can’t tell my customers, ‘it’s not my fault.’ My customers don’t care. They just want good, fast, reliable service."

The Motley Fool implemented the Compaq SAN one year ago and plans to roll out two more this month. Gibbs credits the success of the implementation to hard work among his staff, Microsoft clustering experts and Fibre Channel experts from Compaq. "It wasn’t easy, but in the end it did work. Standard support isn’t going to do it. You have to talk to the people who live and breathe this stuff," Gibbs says. "We’ve been pretty pleased. Consistently, the SAN is not the bottleneck."

Buying Advice

When considering a SAN product, ask the vendor if the solution is proprietary or open, but don’t stop there. Many hardware devices can work with each other, but few of the SAN software products will. For example, if you use Legato products for backup, find out if it will it run on an EMC SAN.

If you buy a SAN from a full-service vendor, such as Compaq or HP, will the company support the other storage products you already have? "Are they really going to be in a hurry to invent the latest driver for their competitors’ products?," asks Walter Hinton, chief strategist at StorageTek.

Does the vendor have an interoperability lab that you can access? Some test and certify that their products work with other SAN technology. To protect your existing storage investment, you may want to use the vendor’s lab to test before you buy.

"Look at the vendor’s track record," says Jeffrey Allen, vice president of marketing and network storage at Sun. "Customers may want everyone to work together now, but that’s not going to happen for a while. Identify the problem you need to solve today and make sure that your vendor has a strategy to go forward."

Be careful of the NT-specific challenges that shared capacity SAN solutions bring, warns David Scott, marketing manager of the enterprise storage business unit at HP. In a shared environment, for example, NT servers act as if they own every storage device they see. To maintain security, NT managers should look for software that provides logical unit (LUn) masking, which hides certain partitions from servers to prevent unauthorized access. Some products even provide device-based LUn masking.

A second challenge arises while switching shared capacity among multiple NT servers, Scott says. When capacity runs low on one server, SAN technology should allow you to allocate storage from another server. But changing the amount of storage allocated to an NT server means rebooting, an impractical approach for sites with hundreds of servers accessed by a SAN. Some software products allow reallocating storage without rebooting, he says.

Future SANs

An additional consideration is engaging a consultant with SAN expertise. Most major vendors and some smaller vendors offer consulting services to help NT managers get SAN strategies up and running.

The alternative is to make the process as simple as possible by using one full-service vendor. "In the next three years, I’d say it’s safe to go with a proprietary solution," NetReference’s Rigney says. "Chances are nothing will change" in the market between now and then.

Aberdeen’s Hill agrees. "You can have a SAN now, but you have to choose your combination of vendors carefully. Customers are mostly staying on the sidelines for now, unless they have a very specific need -- such as a tape library -- a very homogeneous environment or a need for distance."

By 2003, he predicts, storage alliance members will begin to deliver on their promise of openness, thus creating powerful management software that allows NT managers to transform isolated storage islands into a centralized storage utility.

Vendors’ SAN Strategies

Advanced Digital Information Corporation (ADIC) (
Drive-independent manufacturer of data storage products and specialized storage management software, selling SAN components as part of data storage infrastructure.

Brocade Communications Systems Inc. (
Sells Fibre Channel switches and SAN management software, intending to provide support for customers’ SAN islands to scale upward in the future.

Clariion Storage Division, Data General Corp. (
Sells large-scale NT server backup products based on Fibre Channel RAID arrays, including end-to-end Fibre Channel-based SANs, Clariion SANbackup and a LAN-free backup and recovery solution that uses IP over Fibre Channel.

Compaq Computer Corp. (
StorageWorks products offer a full range of storage solutions, including the Enterprise Network Storage Architecture (ENSA), Compaq’s vision for defining an evolutionary SAN storage path. Also offers StorageWorks Virtual Replicator, storage management for NT environments.

CommVault Systems Inc. (
An AT&T Labs spin-off, which originally focused on backup and recovery, now sells Vault98 integrated software suite for high-performance, network-based backup and restore.

Dell Computer Corp. (
Server vendor that sells PowerEdge servers, PowerVault RAID disks, DLT tape libraries and Fibre Channel switch and bridge. Offers turn-key packages that use pretested components.

EMC Corp. (
Successful in the mainframe storage market, EMC has expanded into enterprise storage through the Symmetrix Enterprise Storage product line.

Exabyte Corp. (
Offers prepackaged NetStorM SAN, including tape libraries, FC-managed routers, network management from partners, a network resource manager, SAN backup applications from partners and integration services through resellers.

Hewlett-Packard Co. (
Full-service provider with SAN products including SureStore E switch, node manager and disk array, as well as SureSpan SAN fabric products and SureSoft storage management software. Recently acquired Transoft Networks.

Hitachi Data Systems (
Newcomer to the NT SAN market, now selling SAN products and services designed to assist clients in planning, implementing, and managing SAN-based environments.

IBM Corp. (
Full-service provider marketing SAN technology through its recently announced Enterprise Storage Server and Seascape architecture. Relying on solid consulting reputation to sell SAN services as well.

MTI Technology Corp. (
End-to-end solution provider with portfolio of storage products and data services, including system integration services for customers lacking SAN experience.

Mylex Corp. (
Sells storage technology to eight of the top 10 OEMs, including several who use the equipment as part of their SAN strategies.

nStor Corporation Inc. (
Sells SANStor prebuilt and component-based SAN technologies. In the process of acquiring Andataco (, which offers custom SAN solutions for Fibre Channel and SCSI products.

OTG Software (
NT-based hierarchical storage management system products to help move data more intelligently around the SAN.

Overland Data Inc. (
SAN-compatible backup solutions, including DLT libraries and autoloaders. Attempting to transform from backup hardware vendor through recently announced Fibre Channel Connectivity Initiative.

StorageTek (
OEM component provider to the storage industry, StorageTek is a pure storage vendor with a range of products based on its VISTA framework.

Sun Microsystems Inc. (
Full-service vendor sells StorEdge disk arrays and Starfire servers, and supports Jiro platform for Java developers to create storage management applications.

Transoft Networks (
Recently acquired by HP, claims 3,500 software-based SAN solutions of SAN Manager OS and FibreNet for high-speed access of large volumes of data, including applications such as imaging, ISPs and animation.

XIOtech Corp. (
Provides the Magnitude SAN-in-a-box centralized storage system, which was recently upgraded with a Fibre Channel Arbitrated Loop (FC-AL) connection.