Serving the SANs of time

Vendors are circling the emerging SAN (storage area network) opportunity in anticipation of a feeding frenzy.

They know it is only a matter of time before most larger enterprises jump in and implement SANs.

However, for now only brave early adopters are prepared to chance the unfamiliar and somewhat choppy waters of this developing market.

In the last few months major vendors have given us a flash of their new pearly white SAN strategies at the same time as they bare teeth at one another over development of SAN standards.

So are SANs enterprise ready? How long before SANs are commonplace in enterprises? And how should enterprises plan storage now, in anticipation of SANs? Laura Mason and IDG staff writers reportFrequently likened to the development of LANs which gave an end user the ability to have a single terminal connected to different servers, SANs offer a means to consolidate storage in the enterprise by connecting heterogeneous servers and enterprise storage systems together, in a separate Fibre Channel network.

The SAN vision is one in which consolidated enterprise storage combined with a comprehensive set of management tools takes enterprise storage into a new era.

It is an attractive prospect for network managers struggling to control ever growing storage needs, the development of separate pools of storage in disparate business units or the heavy demands of storage traffic on a LAN.

"There are a lot of very complex computing environments out there which are decentralised and heterogeneous," said Jason Ditcham, Asia area network product manager for Storage Technology (StorageTek).

"Storage is attached to servers, and servers are attached to the network, and many company networks are now in crisis.

"There is a need for companies to recentralise their data management through technologies like SAN," Ditcham said.

Traditional storage solutions using LAN servers, SCSI and use of LAN connections for data backup are imposing limits on network storage, according to Dave Tang, Gadzoox Microsystems.

SANs promise an end to bandwidth bottlenecks and scalability limitations imposed by SCSI bus-based architecture, he adds.

SANs also promise access to data over increased distances.

Whilst SCSI has a distance limit of 25 metres between servers and storage systems, Fibre Channel will allow devices on the network to be separated by up to 10km and further in the future, according to Jim Morris, field sales support manager, EMC.

Vendors know SANs are what users need and they are currently jostling for position, attempting to maximise their SAN market opportunities.

EMC, Compaq, Data General, StorageTek, Hewlett-Packard (HP), IBM, Computer Associates, Veritas, Legato, Exabyte, Dell -- and many others -- are jumping on the SAN bandwagon with solutions ranging from enterprise SANs to management software.

However, despite vendors' spruiking, SAN technology has a way to go before it achieves maturity, and early adopters in Australia have spoken out about interoperability issues.

One of those early adopters is Brisbane-based bank Suncorp Metway.

Implemented over the last six months, Suncorp's SAN is primarily Hewlett-Packard- based, with a Hitachi disk subsystem and StorageTek DLT (digital linear tape) silo.

Suncorp encountered problems when it tried to extend the SAN beyond Unix to NT, according to Howard Charles, technical services manager for mainframe and mid-range systems, Suncorp.

"We found the hub infrastructure from HP wasn't enough when we wanted to expand to NT," Charles said.

Suncorp's HP and NT servers reside on separate Fibre Channel loops.

They share the same disk infrastructure, but "at present we can't share tape drives between HP and NT environments", Charles said.

He expects this situation to be resolved as vendors work to improve interoperability.

"SAN is an emerging technology," Charles said. "You can put in a limited [SAN] implementation as long as you test the equipment and know it all works together."

Charles advises IT managers not to purchase SAN products before testing their interoperability.

He also warned that many vendors are still working on establishing their SAN capabilities, and still building up knowledge in the area.

However, Charles described Suncorp's SAN implementation as "very easy and quick", adding: "It's not as bad as everyone makes it out to be."

Suncorp has experienced immediate benefits from its SAN, reports Charles.

One key benefit was the ability to integrate the enterprise's existing hardware, he said, and accessing data from the disk infrastructure is now faster by up to 75 per cent.

Backups were also quicker with the SAN infrastructure.

"My belief is that the SAN is where all storage will reside in the future and the future isn't too far away," Charles said.

Another Australian early adopter of SAN that has experienced difficulties is Robertson Research (RR) The WA-based seismic data processing company has had problems with data sharing across its SAN. "If you put data on a server and you want to access it on another server you have to access it via the LAN or actually put it on tape [and transfer it] to that server," said Franco Broi, programming manager, RR.

"We need a network file system (NFS) running over the SAN using the SAN as a transport mechanism," he said, adding that he had not been able to find such a system as yet.

"We can't get concurrent access to any one file like you can with NFS," he said.

Broi has also reported difficulties with product support configuration advice from Hewlett-Packard for its tape drives (see Computerworld April 23, 1999, p1).

RR runs two separate Fibre Channel SANs -- one for tape storage and the other for RAID systems -- running more than a terabyte of data using seven HP D390 machines.

Despite the problems, RR has seen some benefits from its SAN implementation.

The swap to Fibre Channel from SCSI has greatly simplified storage wiring, according to Broi. "In that respect it's neat and tidy," he said.

Plus the organisation can now move RAID disks from one server to another without shutting servers down, Broi added.

Vendors admit that SAN technology is not yet fully mature.

Chris Wood at US based storage company Maxstrat, says there are still pieces missing from the SAN jigsaw.

"The hardware infrastructure is in place, but the storage area network puzzle is still missing a lot of pieces," Wood said in a recent white paper, available on the Fibre Channel Loop Community Web site (

"What's missing from the SAN puzzle are file systems, database managers, access methods, and volume managers."

These components read and write data from storage peripherals, and present it to user applications.

And although vendors' platforms incorporate file systems, often they are not interoperable with each other.

"Data structures and file systems are a tower of Babel, and no two are alike," Wood said.

He warns that even in a single-vendor SAN environment, sharing common data can be difficult, since today's file systems were designed for "the traditional single-computer model; they are not aware of, nor can they communicate directly with any other computer's file system".

According to Wood, "Like many emerging technologies, SANs are easier to draw on paper than to actually implement.

"In reality SANS don't really work yet," Wood concludes.

Other users are finding they can't run TCP/IP on their Fibre Channel SANs.

"You can't run (TCP/IP) on Fibre Channel yet," said Page Tagizad, director of product management, Procom Technology.

"So, people are using their existing standard networking topologies, such as Ethernet, FDDI, or token ring. But if they are doing that, then it's not SAN. A true SAN runs Fibre Channel."

As is commonly the case with emerging technology, industry standards for SAN have yet to be clarified.

A race to develop standards has developed with two main groups, -- the Storage Network Industry Association (SNIA) and the EMC-led FibreAlliance -- competing to develop SAN standards.

Questions have been raised over whether this lack of a unified approach to SAN standards in the industry will result in fragmented standards and confusion for users.

However Graham Penn, general manager, research, IDC Australia, believes the end of the battle over standards is in sight.

By the end of Q3 1999, most standards will be in place, he said.

Not everyone is so optimistic. In a recent interview, Bill Marriner, chairman and chief executive officer, Exabyte, said he believed it would be "many months" before standards were established.

"I wouldn't expect to see standards this year. Standards are -- while the industry loves them -- hard to come by. To make standards happen, you've got to get a lot of compromises made by a lot of players."

Meanwhile, Wood estimates that true shared data access will become available over the next several years.

So when will SAN move beyond the early adopter stage?

"Every proponent in our industry says SAN will be a huge market by 2001," said Bruce Taafe, vice president, international field operations, StorageTek.

According to Penn many organisations will have SANs within the next two years.

Steve Bovis, storage marketing manager, Compaq, believes the market will move beyond the early adopter stage "very, very quickly".

Morris thinks "We'll be moving out of the early adopters within 12 months", adding that it may take a little longer in Australia.

Outsourcers and financial institutions are likely to be among the first cabs off the rank, when it comes to implementing SANs.

However, early SAN implementations have also occurred in government and retail organisations.

"There's a lot of people that are looking at [EMC's Enterprise SAN offering] including the likes of outsourcers -- EDS in particular is quite keen on the concept. [SAN] brings the ability to be able to consolidate a lot of disparate platforms, and in an outsourcing environment where you are bringing in new customers -- their platforms are so varied.

It provides a good opportunity to be able to pull all these different hosts into a common storage platform," Morris said, adding that EMC also considers financial institutions and insurance companies to be likely prospects.

Whilst many believe SANs are most appropriate for larger organisations, Penn believes it is not just the big guys who will implement SANs.

Anyone beyond small organisations with two or three servers that can be managed by one person, is crying out for a SAN, Penn said.

Large organisations will be the first to implement but "[SANs] will move fairly rapidly into relatively small environments," Penn said.

So if you are not game to be an early adopter, but see a SAN implementation as inevitable eventually, how should you modify your storage purchasing policy today?

Bovis advises organisations looking to implement SANs in the future to ensure that any storage products purchased now should be able to migrate to a SAN.

They should avoid SCSI products that cannot be upgraded to Fibre Channel, Bovis said, and they should start to deploy Fibre Channel where they can in their current, direct-connect environment.

According to Chris Wood, "IT managers should seriously consider implementing the necessary SAN infrastructure today so that they will be ready to take advantage of true shared data access as it becomes ready over the next several years."

Eileen Yu, Megan Scott and David Legard contributed to this story

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