A methodology wherein two different types of locks are used by a storage manager when multiple clients wish to access a particular redundantly-stored file. Simple byte-range based mutual exclusion (or mutex) locks are granted by the storage manager for data writes/updates to the file when the file is in the fault-free state, and individual readers/writers (R/W) locks are granted by the storage manager when the file is in the degraded state. No read locks are required of clients when the file object is in the fault-free state. During the fault-free state of the file object, when exactly one client is writing to the file object, the storage manger grants that file object a whole-file lock valid over the entire file object. Each client may have a client lock manager that interacts with appropriate storage manager lock manager to request and obtain necessary locks. These various locking mechanisms reduce lock-related network traffic in a data storage system.
REFERENCE TO RELATED APPLICATIONS
This application claims priority benefits of prior filed co-pending and commonly-owned U.S. provisional patent applications Ser. No. 60/368,785, filed on Mar. 29, 2002, Ser. No. 60/372,026, filed on Apr. 12, 2002, and Ser. No. 60/372,024, filed on Apr. 12, 2002, the disclosures of all of them are incorporated herein by reference in their entireties.
