Emc Corporation

Saurabh M Pathak

David Haase

Michael D Haynes

Paul Thomas McGrath

Somnath A Gulve

Miles Aram De Forest

Alan Lee Taylor

Dennis Thomas Duprey

Charles Christopher Bailey

Robert F Goudreau

James Mark Holt

Chetan Rameshchandra Vaidya

William Paul Hotle

Sheetal A Desai

Miles A Deforest

Robert K Dewitt

Somnath A Gulye

Anita I Bezera

An embodiment of a computer-implemented method for use in managing allocation of a storage pool in a data storage system by calculating an allocation mode for the storage pool based on a policy is described. Also described are embodiments of a system and computer program product enabled for carrying out such computer-implemented allocation management.

Calculating an allocation mode for a storage pool based on a policy

Methods, systems, and computer readable media for copy-on-demand optimization for large writes are disclosed. According to one aspect, a method for copy on demand optimization for large writes includes, in a system having a source data storage entity and a destination data storage entity, receiving a write request to write data to a target portion of the source data storage entity, the target portion of the source data storage entity comprising at least one data storage block. The method includes determining whether the source data storage entity and the destination data storage entity are engaged in a backup operation in which data sufficient to synchronize the source data storage entity to the destination data storage entity is copied from the destination data storage entity to the source data storage entity, and if so, determining whether the target portion of the source data storage entity is not yet synchronized to the destination data storage entity. If the target portion of the source data storage entity is not yet synchronized to the destination data storage entity, a copy-on-demand operation is performed to synchronize the target portion of the source data storage entity to the destination data storage entity, where each data storage block within the target portion of the source data storage entity that will be completely overwritten as a result of the write request is not synchronized to the destination data storage entity. The write request to write data to the target portion of the source data storage entity is then processed.

Systems, methods, and computer readable media for copy-on-demand optimization for large writes

According to one aspect, the subject matter described herein includes a method for processing read requests received during a restore operation, where a protected restore operation includes copying at least a portion of the data content of the clone to its source. The method includes receiving a read request to read data from a source during a protected restore operation. It is determined whether to redirect the read request to the clone, and in response to determining to redirect the read request to the clone, the read request is redirected to read data from the clone.

Methods, systems, and computer program products for processing read requests received during a protected restore operation

Systems, methods, and computer readable media for tracking storage pool reservations are disclosed. According to one aspect, the subject matter described herein includes a system for tracking storage pool reservations. The system includes a storage entity having data storage space for storing data, the data storage space being divided into a plurality of slices. The system also includes one or more portions of non-volatile memory, different from the data storage space, for storing slice reservation statistics and information about requests that affect slice reservation statistics, wherein storing information in the portion of non-volatile memory is an atomic operation. The system further includes a control module for receiving a request that affect slice reservation statistics, storing information about the request in the portion of non-volatile memory, performing the request, and updating the slice reservation statistics and clearing the information about the request in the portion of non-volatile memory.

Systems, methods, and computer readable media for tracking pool storage space reservations

Systems, methods, and computer readable media for triggering and coordinating pool storage reclamation are disclosed. According to one example, the method includes receiving an issued hint triggered by the execution of a data storage optimization operation applied to a mapped logical unit (MLU), wherein the MLU is one of a plurality of MLUs residing in a storage array, and computing an unused portion amount of an allocated storage space in the MLU, wherein the allocated storage space comprises a plurality of slices. If the unused portion amount exceeds a predetermined threshold value, detecting at least one of the slices to be released from the allocated storage space. The method also includes transferring data contained in a detected slice to at least one of the remaining slices in the allocated storage space, and removing the detected slice from the allocated storage space in the MLU to a common storage pool in the storage array, wherein the removed slice is allocated to any one of the plurality of MLUs.

Systems, methods, and computer readable media for triggering and coordinating pool storage reclamation

A system and method related to maintaining consistency of replicated data in a data storage environment. The system handles Input/Output (IO)-Requests in a data storage environment having a server and production data stored on a data storage volume on a data storage system. A copy of the production data is stored on another data storage volume of a second data storage system, wherein IO-Requests to update production data are handled so that the data copy is consistent with the production data after processing the IO-Request.

System and method for handling device objects in a data storage environment for maintaining consistency during data replication

Methods, systems, and computer program products for preventing concurrent execution of conflicting software operations on the same and different storage processors while avoiding the deadlocks are disclosed. According to one method, first and second instances of a first software utility for respectively executing on the first and second storage processors having access to a storage medium are provided. First and second instances of the second software utility for respectively executing on the first and second storage processors are also provided. A lock is provided to instances of the first utility. The lock makes exclusive the operations of checking for an activity query from instances of the second utility and receiving a query from instances of the second utility. A first operation implemented by the first utility may fail if the activity query has been received when the checking occurs.

Methods, systems, and computer program products for preventing concurrent execution of conflicting software operations on the same and different storage processors having access to a common storage medium while avoiding deadlocks

Methods, systems, and computer program products for postponing bitmap transfers and eliminating configuration information transfers during trespass operations in a disk array environment are disclosed. According to one method, a clone group is stored on a disk array, the clone group including a logical unit (LUN) representing a storage partition on the disk array and a clone of the LUN, the clone being a copy of the data referenced by the LUN. The clone group is associated with a first storage processor (SP) for writing data to the disk array. Changes between the LUN and the clone are tracked by maintaining a data structure indicative of the changes in a memory associated with the first SP. The association of the clone group is changed to a second SP for writing data to the disk array without transferring the data structure to memory associated with the second SP.

Methods, systems, and computer program products for postponing bitmap transfers and eliminating configuration information transfers during trespass operations in a disk array environment

Growing community of inventors

Jersey City, NJ, United States of America

Saurabh M Pathak