Emc Corporation

Emc IP Holding Company LLC

Chung-Huy Chen

Alan Lee Taylor

Karl M Owen

Robert F Goudreau

James Mark Holt

Dennis Thomas Duprey

David Haase

Michael C Brundage

Charles Christopher Bailey

Michael Paul Wagner

Derek Scott

Techniques for processing requests are described. A first thread is selected for execution. Only a single thread is allowed to execute at a time. Each thread is associated with a queue of requests to be processed by the thread. A first request is selected from the queue of first thread that performs first processing to service the first request. A service time classification for the first request is determined in accordance with criteria that includes a runtime determination of what resource(s) are used in servicing the first request. It is determined, in accordance with the service time classification, whether to allow the first thread to continue execution and process a second request from the queue of the first thread. If the first thread is allowed to continue execution, second processing is performed by the first thread to service the second request. Otherwise, a second thread is selected for execution.

Using request service time as fairness heuristic in locking techniques

Techniques are described for performing a copy operation. A first request is received to perform a copy operation. The first request includes a set of parameters in accordance with a defined interface and include a source area and a target area. The source area includes source ranges and source devices. Each of the source ranges identifies a portion of a logical address range of a different one of the source devices. The target area includes target ranges and target devices. Each of the target ranges identifies a portion of a logical address range of a different one of the target devices. The first request is partitioned in to a plurality of other requests each of which is a request to copy a portion of source data located in the source area to a corresponding location in the target area. The other requests are then issued.

Data movement bulk copy operation

Techniques are described for generating a unique identifier by a first processor using a plurality of values including a shared value, the first processor's identifier, a container identifier and a time value. The shared value is a common value used by a plurality of processors including the first processor. The container identifier identifies a memory location. The time value denotes an amount of time that has elapsed since the first processor was last booted.

Techniques for generating unique identifiers

A technique manages peer messaging across multiple SPs of a data storage array. The technique involves using a token, by a first SP of the data storage array, to identify particular data stored at a source storage location on the data storage array. The technique further involves starting, by the first SP, multiple WUT operations which use the token in response to multiple WUT requests, each WUT operation moving the particular data from the source storage location to a respective destination storage location. The technique further involves providing, by the first SP, a single 'touch' message in response to starting the multiple WUT operations by the first SP, the single 'touch' message informing a set of other SPs of the data storage array that the token which identifies the particular data has been touched.

Techniques for peer messaging across multiple storage processors of a data storage array

Systems, methods, and computer readable media for accessing and compressing data at a virtually provisioned storage entity are disclosed. According to one aspect, a method includes receiving, at a data storage entity, an input/output (I/O) command to perform an operation on data associated with a logical block address (LBA) in a virtually provisioned device in the data storage entity, wherein the data storage entity has established an expanded private LBA space for the virtually provisioned device in the data storage entity to include both a compressed LBA space portion for storing compressed data and an associated uncompressed LBA space portion for storing uncompressed data. The method further includes determining if a data chunk containing the data in the uncompressed LBA space is available using the LBA in the I/O command to access the data chunk. If the data chunk in the uncompressed LBA space is available, the method includes performing the operation on the data chunk. If the data chunk in the uncompressed LBA space is not available, the method includes accessing the data chunk in the compressed LBA space using both the LBA and a predefined offset value and performing the operation on the data chunk.

Systems, methods, and computer readable media for compressing data at a virtually provisioned storage entity

A technique manages token states across multiple storage processors (SPs) of a data storage array. The technique involves using a token, by a first SP, to identify particular data stored on the array. The technique further involves updating, by the first SP, a first SP-controlled set of token state information for the token, the first SP-controlled set of token state information including (i) a first token state which indicates whether the token is 'idle' or 'busy' from a perspective of the first SP and (ii) a second token state which indicates whether the token is &#x201c;idle&#x201d; or &#x201c;busy&#x201d; from a perspective of a second SP. The technique further involves expiring, by the first SP, the token in response to the first SP-controlled set of token state information indicating that the token has remained &#x201c;idle&#x201d; for at least a predefined amount of time.

Growing community of inventors

Cary, NC, United States of America

Chung-Huy Chen