Lsi Logic Corporation

Netapp, Inc.

Forrest Trimbell

Joseph Moore

William Hetrick

Daniel David McCarthy

Mark David Olson

Christopher Cason

James Philip Wittig

Jared Cantwell

Satish Sangapu

A technique is configured to maintain multiple copies of data served by storage nodes of a cluster during upgrade of a storage node to ensure continuous protection of the data served by the nodes. The data is logically organized as one or more volumes on storage devices of the cluster and includes metadata that describe the data of each volume. A data protection system may be configured to maintain at least two copies of the data in the cluster during upgrade to a storage node that is assigned to host one of the copies of the data but that is taken offline during the upgrade. As a result, an original slice service of the node may be rendered unavailable during the upgrade. In response, the technique redirects replicated data targeted to the original slice service to a standby pool of slice services in accordance with a degraded redundant metadata service of the cluster. In the event the standby slice service itself subsequently becomes unavailable, another standby slice service from the standby pool is activated to receive the subsequent data. In this manner, cascading failure of secondary slice slices is handled.

Standby copies withstand cascading fails

The present invention is directed to a method of an adaptive procedure table which is capable of providing default behaviors for each procedure if a corresponding procedure is not defined or has been removed from a software build. The default behaviors for each procedure may be defined in a template file provided by a developer before a compile time of software. The present invention may permit a module that defines the implementation of a procedure to be removed from the software build without requiring source code changes. As such, the developer may be allowed to remove or add certain features from a compiled program without introducing compile time or link time errors.

Adaptive dispatch table based on templates

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Longmont, CO, United States of America

Forrest Trimbell