Emc Corporation

Data General Corporation

James Theodore Compton

Uday K Gupta

Stephen A Fridella

Stephen A Rago

Surrendranath R Doohkan

Nikolay Popov

Roy E Clark

Sorin Faibish

John S Harwood

Robert Anthony Alfieri

Xiaoye Jiang

John T Cardente

Paul Thomas McGrath

Christopher H Stacey

Michael B Evans

Eyal Zimran

Augustine Amegadzie

Jerald W Gross

Eric R Vook

Brian J Thorstad

Khaled S Soufi

Andrew R Huber

Methods, systems, and computer program products for managing quality of service for shared storage accessed by a plurality of nodes are disclosed. According to one method, at a node of a plurality of nodes sharing access to a first disk array, quality-of-service (QoS) metadata associated with a portion of the disk array are requested from a server, wherein the QoS metadata includes at least one performance criterion for the portion of the disk array. I/O performance is monitored for the portion of the disk array in response to receiving the QoS metadata. The monitored I/O performance is compared with the QoS metadata. Based upon the comparison of the monitored I/O performance with the QoS metadata, it is determined whether a QoS violation has occurred. In response to determining that a QoS violation has occurred, the server is requested to migrate data associated with the portion of the disk array.

Methods systems, and computer program products for managing quality-of-service associated with storage shared by computing grids and clusters with a plurality of nodes

An improved policy enforcement architecture includes several components that improve the performance of policy enforcement in a hierarchical storage environment. A File System Query instruction permits a richer set of queries to be expressed by a policy engine, thereby permitting more complex policies to be implemented with ease. The File System result is generated at the file server, and only files of interest are forwarded to the policy engine. The file system query advantageously may be applied against a pre-generated index having one more characterizing attributes to further reduce the processing required to retrieve policy data. An Index Build instruction, added to a programming interface, allows a policy engine generate the characterizing indices in advance of use. Index maintenance techniques maintain consistency between the index and the file system to ensure that the policy can be enforced using accurate file information.

Apparatus and method for maintaining a file system index

A hierarchical storage system is constructed from file servers and a policy engine server by building upon a file migration service. Offline attributes are added to file system inodes in a primary file server, file system parameters are added in the primary server, an offline read access method field is added to a connection database, and the primary file server is programmed to use these attributes and parameters for selecting a particular method (such as a partial read migration or a pass through read method) for read access to an offline file. In this fashion, the primary file server is provided with flexibility for selecting a particular one of a number of migration methods depending on various conditions, in order to improve the trade-off between the cost of storage and delay in file access.

Selection of migration methods including partial read restore in distributed storage management

A caching technique involves receiving a cache request to move data into a cache (or a particular cache level of a cache hierarchy), and generating a comparison between content of the data and content of other data already stored within the cache. The caching technique further involves providing a caching response based on the comparison between the content of the data and the content of the other data already stored within the cache. The caching response includes refraining from moving the data into the cache when the comparison indicates that the content of the data is already stored within the cache. The caching response includes moving the data into the cache when the comparison indicates that the content of the data is not already stored within the cache. Such a technique is capable of eliminating data redundancies within a cache (or within a particular cache level of a cache hierarchy).

Content-aware caching techniques

File system query and method of use

Apparatus and method for building a file system index

Methods, systems, and computer program products for providing access to shared storage by a plurality of nodes are disclosed. According to one method, at a node of a plurality of nodes sharing access to a disk array, an application input/output (I/O) operation and whether sufficient space in the disk array has been mapped at the node for the I/O operation are detected. In response to detecting that sufficient space in the disk array has not been mapped at the node for the I/O operation, a map for the I/O operation including physical disk access information is requested and obtained from a server. The physical disk access information included within the map for the application I/O operation obtained from the server is used to perform the I/O operation by accessing the disk array without intervention by the server.

Methods, systems, and computer program products for providing access to shared storage by computing grids and clusters with large numbers of nodes

A shared-disk cluster system includes a cluster membership manager framework which coordinates the joining or leaving among all nodes in a cluster including taking the multiple layers of involved subsystems through transitions. Subsystems are notified of transitions in particular order depending upon the transition, and all nodes' subsystems receiving a notification must process that notification prior to another layer of subsystems being notified. One of the subsystems registered for notification is an event manager in user space. The event manager carries out transfers of client services, including user applications, resulting from nodes joining and leaving the cluster. This includes a registration and launch service which registers a node, or multiple nodes, in a cluster which claims, or is assigned, responsibility for the service and provides an optional launching function which initiates the client service upon successful registration.

Multiprocessor cluster membership manager framework

Growing community of inventors

Durham, NC, United States of America

James Theodore Compton