Red Hat, Inc.

Jonathan E Brassow

Kenneth William Preslan

Matthew O'Keefe

Michael J Declerck

Andrew Lewis

Adam Manthei

David Teigland

An inter-machine locking mechanism coordinates the access of shared resources in a tightly-coupled cluster that includes a number of processing systems. When a requesting processing system acquires a lock to access a resource, a comparison is made between values of a global counter and a local counter. The global counter indicates the number of times the lock is acquired exclusively by any of the processing systems. Based on the comparison result, the requesting processing system determines whether the resource has been modified since the last time it held the lock.

Augmented advisory lock mechanism for tightly-coupled clusters

A distributed file system is disclosed. A plurality of disk servers, operating as a single distributed disk server layer, are connected to the one or more physical disks. Each disk server stores meta-data for each of the files. A plurality of lock servers, having one or more locks for each file operates as a single distributed lock server to coordinate access to the files stored by the disk server layer. A plurality of asynchronous file servers, operating as a single distributed file server layer in response to a request for a file from a user program: (i) retrieves the requested file from the disk server layer and at least one lock, associated with the retrieved file, from the lock server, and (ii) retrieves meta-data for at least one file that is related to the requested files, and at least one lock, for each file that has had its meta-data retrieved.

Distributed file system using disk servers, lock servers and file servers

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Eagan, MN, United States of America

Jonathan E Brassow