Abstract: A network file server includes a first set of data processors for receiving requests from clients, and a second set of data processors for accessing read-write file systems. A respective data processor in the second set is assigned to each file system for exclusive management of read and write locks on the file system. Each data processor in the first set can authorize access to file systems directly accessed by more than one data processor in the second set. Processing of a request for access that is authorized is continued by the data processor that is assigned to manage the locks on the file system to be accessed. The exclusivity of lock management eliminates cache coherency problems, and dynamic load balancing can be used to prevent the lock management from becoming a bottleneck to performance. A preferred embodiment includes a cached disk storage subsystem linked to data mover computers.

Abstract: A network file server includes a first set of data processors for receiving requests from clients, and a second set of data processors for accessing read-write file systems. A respective data processor in the second set is assigned to each file system for exclusive management of read and write locks on the file system. Each data processor in the first set can authorize access to file systems directly accessed by more than one data processor in the second set. Processing of a request for access that is assigned to manage the locks on the file system to be accessed. The exclusivity of lock management eliminates cache coherency problems, and dynamic load balancing can be used to prevent the lock management from becoming a bottleneck to performance.

Abstract: A network file server includes a first set of data processors for receiving requests from clients, and a second set of data processors for accessing read-write file systems. A respective data processor in the second set is assigned to each file system for exclusive management of read and write locks on the file system. Each data processor in the first set can authorize access to file systems directly accessed by more than one data processor in the second set. Processing of a request for access that is authorized is continued by the data processor that is assigned to manage the locks on the file system to be accessed. The exclusivity of lock management eliminates cache coherency problems, and dynamic load balancing can be used to prevent the lock management from becoming a bottleneck to performance. A preferred embodiment includes a cached disk storage subsystem linked to data mover computers.

Abstract: A conventional network file server has a file system that permits file attributes and file data to be written in any order. The conventional network file server may also support an asynchronous write protocol, in which file attributes and file data need not be written to disk storage until a client sends a commit request. This asynchronous write protocol has a data security problem if the attributes are written before the data and the server crashes before completing the writing of the data to disk storage. This security problem is solved by adding a file system cache and following a protocol that writes the attributes to storage after writing the data to storage. For example, the attributes and data are stored in the file system cache and are not written down to storage until receipt of a commit request. When the commit request is received, the data is sent first from the file system cache to storage. Then the attributes are sent from the file system cache to storage.