Archivas is launching into direct competition with EMC's Centera storage system with the release of its ArC cluster product at half the price.

ArC is an object-based file system storing only one copy of each data object through a content-addressing scheme. Archivas claims it is unique in being able to share its stored data between multiple applications. It is currently in beta test at the NASA Goddard Space Flight Centre but is expected on the market by September.

The system is NAS-like in its use of standard interfaces such as CIFS (Windows) and NFS (Unix/Linux). It is also scalable with clustered nodes. Each node can hold 50 million objects and there can be hundreds of nodes. That means petabytes of potential storage capacity.

A file is stored as an object along with its meta data - data describing its properties - and file policies. These policies can be used to help support regiulatory and compliance needs.

EMC's mould-breaking idea was to store reference data - records needing to be kept but with low access neeeds, such as mortgage records - in a dedicated disk-based storage device. It used hash-based content addressing to ensure no duplicates were stored and serial ATA drives to lower the cost. However, the Centera device has a proprietary interface, necessitating EMC-partner-supplied software to use it, and only EMC hardware can be used.

Asim Zaheer, VP Marketing for Archivas, said: "The users' primary need is to share an archive amongst multiple applications. The problem is that EMC Centera is dedicated to one application. EMC has a proprietary CAS interface, not an open interface. Ours is completely open and we can be shared. Our backend storage is completely open too. We can support multiple heterogeneous storage. EMC has a 'closed cabinet'."

ZAheer also says the Archivas system will be more cost-effective; "We're targeting a total system cost of one cent per megabyte or ten dollars per gigabyte. EMC is at least double that price."

The number of fixed content disk-based schemes is increasing. Ones from Permabit and Avamar were described here. CAS is also used by Exagrid. That company's clustering marks a similarity between it and Archivas.

The responsiveness and scalability of fixed-content disk storage is providing a strong alternative to tape as the storage medium for fixed-content or reference data. Tape is still viewed as the archive of last resort though.