Cleversafe is an open source platform that allows for the creation of Dispersed Storage Networks (dsNet), which in turn allow an individual to store data securely on a grid of multiple, remote, network/Internet accessible servers. I.E., data that the user wishes to store on the grid is automatically broken up into multiple slices, each of which is unrecognizable in and of itself, with each slice stored on a separate server. No one slice contains all of the data within the file (the developers state that the individual slices do not contain enough information for an unauthorized viewer to determine the original content), and the platform enables RAID-like protective capabilities in that only a portion of the available servers need be reachable in order to recover the stored data.

Both the width of the dsNet (the number of Slicestor servers--see below for definition) and the threshold of the platform (the number of servers that need to be reachable to recreate the stored data) can be configured by the dsNet administrator, depending on storage and reliability needs. For example, in a dsNet with a width of 16 and a threshold of 10, stored data is programmatically broken up into 16 slices using Cauchy Reed-Solomon Information Dispersal Algorithms (IDAs). These slices are then transported encrypted to each of the 16 repository servers, where the slice is stored. From then on, the complete data can be recovered from any 10 of the available servers in the dsNet; i.e., up to any 6 of the individual storage servers can fail or be unreachable, with the data still being able to be recovered from the remaining 10. Because the data is sliced into chunks, the vendor notes that the IDA-based approach requires less overall resources than strictly copy-based protection schemes, while tolerating more device failures than typical parity (i.e., RAID) schemes.

Cleversafe access is based on iSCSI, and therefore the storage grid to available to iSCSI initiators on the source computers. The three current components of a fully deployed dsNet platform include:

- An Accesser, a Linux-based box that provides an iSCSI target for collected storage servers of the grid. The Accesser provides the ability to slice data for dispersal to the dsNet or reassemble data collected from the dsNet; exposing the dsNet itself to the source computer as part of the source computer's own file system.

- Slicestor servers, Linux-based boxes, each of which can be geographically dispersed around the world and will hold the individual slices of data. Because the IDAs slice data into unrecognizable segments, the vendor notes that even if a Slicestor were compromised and its encryption broken, the individual data slices would still not present enough information to recreate the original data.

- dsNet Manager, which provides fault management and performance monitoring features for the full dsNet deployment. Monitored actions include authentication attempts, load, memory, stress level, memory buffers, and more. Access is via a Web interface, with SNMP-based communications also supported.

The Manager makes setting up and monitoring a dsNet a snap-both are done via an easy-to-use web-based interface that not only speeds up deployment of the dsNet, but also allows remote management of the network.

While the current release focuses entirely on block-based access to the dsNet via iSCSI, the vendor notes that planned future interface developments include support for FTP, NFS, CIFS, and WebDAV-based storage.

In addition to the open source Cleversafe site, Cleversafe (the company) operates its own site offering commercial grid storage support and services, as well as pre-loaded appliance versions of each of the above components. In particular, the vendor has announced the rollout of a commercial dsNet grid, with dsNet components hosted by five Cleversafe partners (Dispersed Storage Providers, or DSPs). The partners will themselves offer storage to their customers on the grid, and Cleversafe will themselves use the grid for their own production data and for customer trial usages.

Visit the Cleversafe Web sites for further information.