DFS (distributed file system) manages multiple, geographically dispersed storage devices, including Fibre Channel and network-attached storage servers.
Although DFS players take slightly different approaches in their products, each presents one file system image to the application server or client seeking file services. Instead of being serviced via Network File System from three NAS servers today - and thus having at least three file systems mounted to your NFS client software - you would only have one mount point to the DFS.
For DFS to interplay effectively with the various file systems that come with NAS devices (NFS for Unix boxes and Common Information File System for Microsoft servers), vendors tweak the technology in myriad ways for maximum storage performance, says Mike Kahn, chairman of The Clipper Group, a technology acquisition consultant. "In one instance, a singular file system takes over for many servers. In others, a metafile server 'floats' overhead," he says. "Others use an installable file system or stub to replace the operating system's native file system."
Whatever the technique, many users find promise in the idea of centralizing storage resources in a single pool.
From Distributed file system on tap, Network World, 09/09/02.
