Storage protocol gains heavyweight support

Major players in the storage industry are collaborating on a file access protocol for direct access to storage, which they claim promises massive performance improvements for ecommerce and database applications.

The protocol, called Direct Access File System (Dafs), is designed to enable a next generation of high-performance, low-latency storage networks, and has been backed by Intel and storage giants Seagate and Network Appliance.

Steven Kleiman, chief technology officer at Network Appliance, who visited London this week to promote the protocol, said Dafs is the "killer app" for clustered environments.

"Dafs allows a performance better than directly-attached storage but with a file access protocol," he said.

Dafs enables direct memory-to-memory file access and uses the Virtual Interface (VI) architecture as its underlying transport mechanism. VI allows bulk data transfer directly to or from application buffers and permits applications to access VI-capable hardware directly without operating system intervention. Infinband, the next-generation server bus architecture, is VI-compliant.

Network Appliance said Dafs, which is suitable for heterogeneous data-sharing environments, promises performance improvements of around 40 per cent through allowing applications to directly access I/O.

However, Jim Porter, president of storage analyst Disc-Trend, said Dafs is "not stable" because it is still under development and needs the support of server vendors before it promises to make any impact on the industry.

"There are a wide variety of interfaces which the standard must address - it needs to be refined and defined. There are a lot of rival approaches and the vendors behind Dafs will have to persuade the rest of the world to climb on board," said Porter.

An organisation called The Dafs Collaborative has been set up by Intel, Seagate and Network Appliance to obtain feedback before the file system is submitted to an appropriate standards body. The first meeting of the group will take place later this summer, with a specification due by the fourth quarter of this year.