Increased file availability and network efficiency in DFS is provided through three mechanisms: replication, caching and multihomed file servers.
· Replication increases file availability by allowing DCE LFS filesets to be replicated on multiple server machines; this minimizes the effects of machine outages. If one machine housing a read-only copy of a DCE LFS fileset is unavailable, other replicas of the fileset are usually still available from other machines.
· Locally caching data decreases access time to the data. The cache is an area of a client machine's local disk or memory dedicated to temporary data storage. Once data is cached, subsequent access to it is fast because the client machine does not need to send a request for it across the network. Thus, caching also minimizes network traffic. As noted previously, DFS ensures that each client housing cached read/write data always has access to the most-recent version of the data; in the case of cached read-only data, DFS ensures that each client has access to the most-recent version of the data within a configurable period of time.
· Multihomed File Servers both help administrators make efficient use of their networks and increase file availability. Network efficiency is improved by allowing administrators to create connections between file servers and the subnetworks or networks wherein most of the DFS clients reside. Multiple network connections per File Server also increases file availability in that a fault in one section of the network is less likely to make a File Server unavailable.