Coda at least allows replication of data among several servers. Coda has the best support for disconnected operation: clients record a log of all file system calls while disconnected, which is then replayed upon reconnection.
Some of the key differences in motivation between traditional distributed file systems and our work can be found in the Coda paper: ``Servers are like public utilities...they are carefully monitored and administered by professional staff.'' ``Disconnected operation...represents a temporary deviation from normal operation.'' We expect that neither of these assertions will hold true in the future.