By Lisa Coleman
Citing limitations inherent in current network-attached storage (NAS) architectures, Scale Eight is developing an alternative NAS technology via its Distributed Storage Software (DSS), which enables large-scale single-image NAS pools that can scale to hundreds of terabytes, according to company claims.
Scale Eight, which provides global storage systems that store, manage, and serve files over the Internet, plans to make its software available in the third quarter of this year. The software will be included in a pre-integrated node using an Intel-based architecture combined with IDE and/or SCSI drives.
To use DSS from a LAN, a user will connect to a NAS pool via a Gigabit Ethernet switch. The pool itself is connected to the switch on the front-end for data transfer, and a separate control/maintenance network is connected to the back-end via another Gigabit Ethernet switch. To the LAN, this configuration looks like one NAS appliance, but it is an unlimited series of nodes. The software supports the NFS and CIFS protocols.
NAS pools offer more scalability than traditional "single-head" NAS devices, are easier to manage, and do not require proprietary hardware or software, according to Patrick Rogers, executive vice president, marketing and business development, at Scale Eight.
Conventional NAS is a stand-alone device that includes storage and a server on its front-end to handle protocols such as NFS and CFS. If users want to scale their NAS systems, they have to add devices one by one. Scaling beyond two or three boxes creates some challenges, according to Bob Passmore, research director for storage at Gartner Inc.
"[With the DSS technology] it's possible to put multiple servers in multiple locations and yet they all act as if they are running the same file system simultaneously," says Passmore. "Scaling and management are much easier. That's a fairly unique capability right now."
Two components comprise DSS software: A distributed file system, called 8FS, enables a number of NAS heads to be pooled in a single data center or between multiple geographic locations. 8FS is a production file system with distributed management capabilities. DSS also includes a distributed logical volume manager (DLVM) that virtualizes direct-attached or SAN-attached block-storage devices into one or more logical volumes.
Geographically dispersed sites using DSS can read/write to the same file system, cache hot files, or mirror the entire file system. The software uses block-level delta updates to minimize network traffic.
Scale Eight considers itself a software company but it once carried the SSP moniker.