Recovery from failure of a data processor in a network server

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 locks on the file system. The file server can detect failure of a failed data processor and automatically recover from the failure. When a failure of a data processor in the first set is detected, a spare data processor is programmed with the logical and physical network addresses of the failed data processor so that the spare data processor assumes the network identity of the failed data processor. When a failure of a data processor in the second set is detected, responsibility for management of the locks on each file system managed by the failed data processor is transferred to an operational data processor. Preferably the responsibility is transferred to the operational data processors in such a way as to balance loading on the operational data processors. The data processors can be commodity digital computers for low cost, and a cached disk storage subsystem or file system caches and remote dual copy techniques can be used to ensure high performance and high data availability.