Emc Corporation

Netapp, Inc.

Andrew W Leung

Windsor Hsu

Kevin M Greenan

Shankar Pasupathy

Minglong Shao

Timothy Clayton Bisson

A method and apparatus to control and manage a power state in a related set of storage devices is described. In one example a method includes, determining an idleness measure at the file system, the idleness measure indicating availability requirements of the device set, and setting an idle state based on the idleness measure. The method also includes receiving the idle state setting at the storage subsystem, determining whether the idle state setting is different from a current state of the device set, determining whether to change the idle state of the device set if the idle state setting is different from the current state of the device set, the determining being based on information about the device set. The method also includes commanding the device set to change the current idle state to correspond to the idle state setting based on determining whether to change the idle state.

Method and apparatus to manage and control a power state of a device set based on availability requirements of corresponding logical addresses

A method and apparatus to exercise and manage a related set of power managed storage devices is described. In one example a method includes receiving a request to allow a transition of the set of storage devices from a first power state to a second power state, determining a wear level for each device in the set, comparing the determined wear levels to thresholds, testing data integrity for each device in the set, and if the wear level does not exceed the threshold and the data integrity tests are passed, then commanding the requested power state transition.

Method and apparatus to exercise and manage a related set of power managed storage devices

Method and apparatus to determine an idle state of a device set based on availability requirements corresponding to the device set

Example embodiments provide various techniques for fast and efficient search of attributes stored in data structures. The attributes are organized following a hierarchical structure of the file system and, in an example, the attributes are stored in a data structure where the hierarchical structure is maintained. As a result, a search within such data structure may follow one or more paths along the hierarchical structure of the file system. Attributes associated with directories and files outside of the path can be excluded from the search. Example embodiments also provide various techniques for updating signatures associated with the attributes. In an example, updates to the signatures can be made incrementally. For example, signatures can be updated when the attributes change.

Search and update of attributes in file systems

Embodiments of the present invention provide mechanisms that overcome limitations of existing indexes by creating two-dimensional (2D) spatial indexes to quickly locate data containers that match two or more predicates. This is accomplished by representing metadata attributes describing a data container as dimensions in a 2D space so that a data container can be expressed as a point or a cell in a 2D space with coordinates being a pair of values of the selected attributes. A space filling curve is used to traverse the 2D space and convert each pair of the 2D coordinates to a single space filling curve value. A 2D spatial index is then created based on the computed space filling curve values so that one value can be associated with one or more points (data containers) in the index. Advantageously, the created spatial index provides for searching and processing fewer metadata entries, thereby decreasing the time typically used to search for data.

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Pleasanton, CA, United States of America

Andrew W Leung