Storage vendors go head to head in standards fight

It is said that the good thing about standards is there are so many of them to choose from, many of them being proprietary. Storage is certainly no exception to this rule. Companies looking for ways to consolidate rapidly expanding storage volumes are, in many cases, eyeing storage area networks. But potential users should be advised: The technology is still maturing and storage vendors have been fighting among themselves about how best to set those standards.

Luckily, it seems likely that storage vendors, including the major players Network Appliance, EMC and IBM, are starting to react to the demands of their corporate customers and are developing stronger cross-vendor standards.

"There is still a lack of agreed standards and it will take another two years before there is any coherent model from the major vendors," said Rakesh Kumar, programme director of datacentre strategies at the Meta Group.

"There are big egos and vested interests in all the proposed standards, but the sheer volume of the market means momentum will gather to push through an agreed standard. This market will dictate how standards will evolve."

The most important standards will be those for communications and interfaces because they will be the fundamentals on which future business systems are built. However, it is likely to take more than two years before the technologies will be suitably established, and until then, the standards wars between the vendors will continue.

Standards wars: the contenders

In the blue corner stands IBM, the company that used to dominate the market for large data centre storage, before it lost most of its share to EMC. In the other corner stands EMC. As a dominant storage vendor, EMC had, in the past, taken both standard and Raid product initiatives in the Sans area. EMC is the de facto leader of the Fibre Alliance, an assemblage of storage vendors seeking to implement Sans as Fibre Channel-based networks.

EMC formed the Fibre Alliance in February 1999 for the purpose of submitting its version of an MIB (Management Information Base) to the Internet Engineering Task Force, the body that has determined several key internet standards. EMC and Hewlett Packard were two of the more prominent backers of the proposal. The MIB is a group of parameters, or variables, whose values define and describe the status of a network and its components. The MIB provides a heterogeneous method of managing multiple Connectivity Units across a SAN.

However, the SNIA (Storage Network Industry Association) had planned to author an MIB proposal of its own. The Fibre Alliance was not interested in taking the initiative in other areas of San specification. The ball remained in the SNIA's court on many of them.

At a meeting of its working group in May 1999, SNIA decided the best way for it to participate in the MIB-setting process was to comment extensively on the Fibre Alliance's proposal, But to many, the exchange between the two groups was indicative of a standards leadership void. And many thought that no-one was setting any standards at all, despite protestations from the key players.

It also became more apparent that the speed of the network had increased faster than the speed of the data channel. The Fibre Alliance and SNIA were struggling with setting standards for Fibre Channel technology that doubled in speed from 100 megabytes per second to 200 megabytes per second. That, coupled with Gigabit Ethernet soon to jump to 10 Gbps, made the need to concentrate on one evolving standard more necessary than ever.

Standards depend on the customer

That was then, and a lot of bridge building has been done since. Storage vendors should be in a better position to meet a wide range of requirements just so long as new standards are adopted and quickly.

"Standards have to be driven by customers' needs. There aren't a lot of storage area networks in place at the moment and that has meant standardisation has been driven by technology rather than by what is wanted by customers. It will be another five years before we see the move to true open standards and not ones defined by vendors' proprietary systems," said Neil McMenemy, chairman of the UK Computer Measurement Group.

A major step was taken at the end of last year at the Storage Networking World Conference in Orlando, Florida when the SNIA agreed on the specification of the interface for the all-important Fibre Channel Host Bus Adapter (HBA). This is a critical component needed to make different storage area network (San) systems interoperate. In addition, it will allow innovative independent software vendors to add greater functionality to San-based systems.

The SNIA also aims to be an independent arbiter of San interoperability, having grabbed the nettle of establishing an independent test facility. The organisation has worked with Compaq to produce what it claims is the largest independent storage network in the world, designed specifically as a testing environment for all San systems.

Many San vendors have already set up their own testing facilities, but these have been limited in scope and have tended to test interoperability of only a few systems. The rate of growth in storage and San systems means that customers want all systems from all vendors to interoperate.

Such interoperability is far more important than the brute performance of any one vendor's systems, though this has not stopped many vendors trying to convince users that their Fibre Channel systems can run at 2Gbit/s transfer speeds, while the reality is that most manage barely half that.

Two gigabits and beyond

But the appearance of standards that improve interoperability will encourage the development of technology that can reach 2Gbit/s and beyond. This process will in turn be aided by the appearance of standards in another area of IT ð processor-to-processor communications.

The proposed InfiniBand inter-processor communication standard, which is being developed by such server specialists as IBM, Sun, Compaq and Dell, could have a leading role. The idea is to overcome what will soon be a major bottleneck in systems design, by increasing the speed with which data can move in and out of the processor.

With the probability of Fibre Channel-based Sans delivering data at 2Gbit/s, processors will need to match that performance level. This is what InfiniBand could do. The sponsors are targeting 2.5Gbit/s transfer rates, and are pitching at 6Gbit/s in the longer term.

And while network administrators wait for Fibre Channel standards to be developed, Internet Protocol is rapidly gaining ground as an alternative storage interface.

One reason is that administrators are beginning to get the tools to make storage over IP, or SOIP, a reality. Nishan Systems has already released a complete set of SOIP products, comprising several switches and management software.

However, some experts question using such a protocol because storage systems don't tolerate latency and lost data packets.