DAFS adds persistent and auto-recovery locks to help clients identify and recovery from this situation.
In addition to tools supporting client fail-over, DAFS provides for server fail-over, as well as migration mechanisms to accommodate failures, growth, and upgrades in 7x24 environments.
The DAFS changes involved in this remapping of how requests are transcribed are extensive, but they don't affect NFSv4 semantics at a fundamental level.
This approach, therefore, is intended for high-performance applications that are sensitive to either throughput or latency, or applications that can make use of the extended DAFS services made available through the user API.
If the file is on a DAFS file system, then the kernel passes the I/O request to the DAFS VFS/IFS, which issues DAFS requests to a server.
The advantage of this type of DAFS client implementation is that applications can use it transparently, just like other remote file system implementations (NFS, AFS, DFS for Unix, CIFS for WinNT/Win2k).