Confusion reigns over storage standards

Over the next few years, network managers are expected to spend three-quarters of their budgets on storage systems. But the fast-changing nature of the market means they will have to face the difficult choice of which offerings to put their money on.

The driving force behind the current growth of the storage market is the internet. The net's huge libraries of content, which range from corporate data to videos, all need to be put into some sort of storage facility.

Chris Atkins, storage marketing manager at Sun Microsystems, says that potent storage techniques have emerged as the sector has developed. But the absence of standards means that products based on these different architectures cannot interoperate with each other, so choosing one may feel like crossing the point of no return.

"Sun believes that the next development in storage will be a single management architecture," says Atkins. "This will integrate all types of storage, no matter where it is, and will allow the network manager to control it from a central point. Until then, there are three storage options available to network managers, and choosing between them carries the risk of losing interoperability."

Send in the Sas
The first and oldest option is to attach storage systems directly to a server, and this model is used in nine out of 10 instances. But analysts believe that this proportion will drop to 60 per cent within three years.

Server-attached storage (Sas) works well for a single application such as a data warehouse that is managed by one project team. This model tends to create separate islands of storage, however, which makes it less appropriate for use in corporate networks.

The second option is to create a separate fibre optic network or storage area network (San). Sans provide network managers with nearly limitless storage capacity because data can run quickly over the fibre channels without putting pressure on existing local area networks (Lans). This means it has become a favourite choice for use with business-critical applications.

But the lack of standards in this area makes it difficult to implement and manage. Interconnectivity standards, in particular, are still immature, which means that different switches will not work together. As a result, Sans become problematic if organisations are keen to use more than one supplier.

The third option is network attached storage (Nas), which involves plugging a box with extra storage capacity into an existing Lan. This option works well for low-end storage needs and is easy to implement, but the Lan needs to be a performant, for example, Ethernet-based one if the architecture is to work efficiently.

Although the recent explosion in Nas system sales can be attributed to the offering's ease of implementation, Sun's Atkins claims its long-term future is limited. "You just plug it on to the Ethernet and it works. Nas is a good solution for now, but in the end, it is not enough for business-critical applications," he said.

"It's like having a catflap in your door, using Nas just for small applications. In the end you think 'well, the cat could just use the main door'," he added.

Two-horse race
Stuart Gilks, technical service manager for Network Appliance in Northern Europe, says that during the past 18 months, customers have been split between buying Nas and San-based systems, and have had to choose just one of them.

But he believes the future of the market lies in the convergence of the two. "At the moment, it is like choosing which horse to bet on. It is important to remove the uncertainty of that choice," he said.

In the meantime, several initiatives to create industry standards have emerged, and these are expected to bear fruit anytime between next quarter and next year.

The Storage Network Industry Associates (SNIA) consortium has managed to win the agreement of its 120 industry members to develop and adhere to standards for fibre channel networks. Its switch manufacturer members have also agreed to adopt a standard that will enable users to deploy different vendors' switches in the same San and have them work together.

Network Appliance, meanwhile, has joined the open storage network initiative to develop Direct Access File System (Dafs), a standard protocol that will enable files to be shared between different storage networks.

Setting the standard
"With Dafs, it no longer matters which horse you bet on," claims Gilks. "You will not lose your investment, because it allows you to integrate with both and leverage the infrastructure."

Last year, Sun also unveiled its Giro initiative, which is intended to enable any Giro-compliant San product to communicate with any other. "Giro follows the Java principle," says Atkins. "Other suppliers can start developing products in their own area of expertise, and that's where the growth in this market is going to happen."

He adds that in future, the applications themselves will be able to add extra storage capabilities to the network as required without the need for human intervention. "We will move to a concept in which the disk tells the system how full it is, and centralised management software will use that information to get the most out of the available space," he argued.