Emc IP Holding Company LLC

Emc Corporation

John P Didier

Philippe Armangau

Ivan Bassov

Sorin Faibish

Matthew H Long

Morrie Gasser

Ajay Karri

John Victor Burroughs

Douglas E Peeke

Rustem Rafikov

Adrianna D Bailey

Bruce A Zimmerman

There is disclosed techniques for data reduction reporting in storage systems. For example in one embodiment, the techniques comprise update a counter denoting an amount of data reduction obtained when a data reduction feature associated with a data reduction requirement is enabled in the storage system when one or more allocation units in a storage system satisfy a data reduction requirement of the storage system. The techniques further comprise generating a snapshot of at least a portion of a file related to the said allocation units such that a first relationship exists when the snapshot is generated and a second relationship exists when the snapshot or the file is updated. The techniques also comprise determining a data reduction attributed to the data reduction feature based on an amount of data reduction denoted by the data reduction counter and an amount of sharing and/or unsharing of indirect blocks including mapping pointers in the relationship between the snapshot and the file.

Data reduction reporting in storage systems

A method of performing deduplication includes (1) receiving a write command that specifies a set of data, the set of data including multiple blocks of data, (2) hashing a subset of the set of data, yielding a representative digest of the set of data, and (3) performing deduplication on the set of data based at least in part on matching the representative digest to a digest already stored in a database which relates digests to locations of data from which the digests were produced. An apparatus, system, and computer program product for performing a similar method are also provided.

Deduplication of large block aggregates using representative block digests

There is disclosed techniques for use in managing data storage in storage systems. For example, in one embodiment, there is disclosed a method comprising receiving a request to store data of a data object in a storage system. The method also comprising determining that at least a portion of the data is to be stored in an uncompressed format in the storage system in response to receiving the request. The method also comprising storing at least a portion of the data in the uncompressed format in an allocation unit of a segment in the storage system such that the stored data in the uncompressed format emulates stored data in a compressed format based on the said determination.

Managing data storage in storage systems

Technology for dynamically adjusting a process scheduler in a storage processor of a data storage system. An average amount of host data contained in sets of host data processed by host I/O request processing threads is calculated. An average amount of time required for each host I/O request processing thread to execute to completely process the average amount of host data contained in a set of host data is also calculated. Operation of the process scheduler in the storage processor is then adjusted to cause the process scheduler to subsequently allocate the processor in the storage processor to host I/O request processing threads in timeslices having a duration that is at least as large as the average amount of time required for each host I/O request processing thread to execute to completely process the average amount of host data contained in a set of host data.

Dynamic adjustment of a process scheduler in a data storage system based on loading of the data storage system during a preceding sampling time period

A data storage system has a chassis and a pair of printed circuit boards disposed in the chassis. Each one of the pair of printed circuit boards has disposed thereon a processor, a translator controlled by the processor, a SAS expander having a bidirectional front end port and multiple bidirectional backend ports, and an expansion port, and a SAS controller coupled between the translator and the expander. The system also has an interposer printed circuit board disposed in the chassis, and multiple multiplexers disposed on the interposer printed circuit board. Each one of the multiplexers has a pair of bidirectional front end ports and a pair of bidirectional back end ports. A first one of the pair of bidirectional front end ports is connected to a corresponding backend port of the SAS expander disposed on a first one of the pair of storage processor printed circuit boards. A second one of the pair of bidirectional front end ports is connected to a corresponding backend port of the SAS expander disposed on a second one of the pair of storage processor printed circuit boards. The system also has multiple disk drives disposed in the chassis. Each one is coupled to at least one backend port of a corresponding one of the multiplexers.

Growing community of inventors

Westborough, MA, United States of America

John P Didier