Emc IP Holding Company LLC

Dell Products Inc.

Ao Sun

Lu Lei

Gary Jialei Wu

Yu Teng

Chen Xiao Wang

Ronnie Yu Cai

Wesley Wei Sun

You Chen

Yunhai Gong

Chun Xi Kenny Chen

Jialei Wu

Kalyan Chakravarthy Gunda

Xingshan Wang

Xiaochen Liu

Mikhail Danilov

Wei Gao

Konstantin Buinov

Shashwat Srivastav

Dong Wang

Sriram Sankaran

Jun Luo

Jian Gong

Julius Jian Zhu

Jiang Cao

Chark Wenshuai Yu

Willa Lang Yuan

Aaron Yurun Wu

Yi Ye

Yurun Wu

Shu Jiang

Lemonie Mengchi Li

Chunxi Cheng

Peter Jie Song

Xiaoxiao Mao

A system can determine a first correlation between respective percentages of stored garbage and respective amounts of garbage of a block storage system based on determining the respective amounts of garbage among first blocks of the respective blocks that satisfy respective criterions of the respective percentages of stored garbage. The system can, based on the first correlation, determine a second correlation between an estimated throughput applicable to reclaiming garbage in the block storage system and the respective amounts of garbage of the block storage system. The system can, based on the first correlation and the second correlation and for a specified target reclamation throughput, determine a corresponding first percentage of stored garbage of the respective percentages of stored garbage. The system can perform copy-forward garbage collection on second blocks of the block storage system that satisfy a criterion defined with respect to the first percentage of stored garbage.

Dynamic tuning of garbage threshold to reduce unreclaimable garbage overhead

The technologies described herein are generally directed toward retrieving data from streaming storage. In an embodiment, a method can include receiving an application data request that identifies application data to be retrieved from a sequence of stored data chunks that correspond to a stored stream of data. The method can further include, based on the application data request, estimating a first estimated location of the application data, with the first estimated location including an identified chunk of a sequence of chunks. Further, the method can include, based on the application data request and a characteristic of the identified chunk, retrieving, by the system, a first data block that is estimated to comprise the application data, resulting in a first retrieved data block.

Retrieving data from streaming storage

Management of a storage system is enabled. In an example, a partition index associated with the partition is obtained, the partition index comprising a group of nodes, a node in the group of nodes indicating metadata of an object in the group of objects. A valid node in the partition index is identified, the valid node indicating valid metadata of an object associated with the valid node in the storage system. A local index for the partition index is generated based on the valid node. In response to receiving an access request for a target object in the group of objects, the target object in the storage system is accessed based on the local index. With the foregoing example implementations, metadata in the storage system may be accessed more efficiently, and the overall response speed of the storage system may be increased.

Method, device, and computer program product for managing storage system

Techniques for processing an access request and updating a storage system are provided. For instance, a method comprises: receiving an access request for an object associated with a storage system, the storage system including a plurality of physical nodes, each of the plurality of physical nodes including at least one set of virtual units, each set of virtual units including at least one virtual unit; determining, from a plurality of sets of virtual units included in the plurality of physical nodes of the storage system, a target set of virtual units associated with the object; and determining, from the target set of virtual units, a target virtual unit corresponding to the object. With the technical solution of the present disclosure, not only a set of virtual units on a physical node may be easily split and merged, but also huge computing resources that need to be allocated may be saved, so better user experience may be brought about at a lower cost.

Methods, devices, and a computer program product for processing an access request and updating a storage system

Embodiments that process data are described. For instance, a method includes receiving, at a first disk management device in a storage system, an access request for accessing data in a plurality of disks associated with the storage system. The method further includes determining whether a first access engine for accessing the plurality of disks in the first disk management device is available. The method further includes redirecting the access request to a second disk management device in the storage system if it is determined that the first access engine is unavailable, wherein a second access engine in the second disk management device is available to access the plurality of disks. By means of this method, effective data access can be performed when an access engine of a disk management device is unavailable, thus realizing a more stable access capability and improving the user experience.

Redirecting access requests between access engines of respective disk management devices

Embodiments of the present disclosure relate to a method, an electronic device, and a computer program product for storage management. According to an example implementation of the present disclosure, a method for storage management includes: acquiring, at a host, a target response entry from a response queue, wherein the response queue includes at least one response entry associated with at least one storage device in a storage system which has been accessed by the host, and the target response entry records information about a target response of a target storage device in the at least one storage device to an access operation initiated by the host; determining, based on the target response entry, whether a failure associated with the target response occurs; and acquiring the target response based on the target response entry if it is determined that no failure occurs. Therefore, the storage performance can be improved.

Method, electronic device and computer program product for storage management

A storage system is managed. For example, in response to a request at a first storage node for data related to a second storage node, it is determined whether the first storage node and the second storage node belong to the same storage node group having an interconnection structure. If it is determined that the first storage node and the second storage node belong to different storage node groups, data is transmitted between the first storage node and the second storage node based on a mapping between storage nodes in a first storage node group with the first storage node and storage nodes in a second storage node group with the second storage node. Thus, data transmission can be performed between different storage node groups through a mapping relationship.

Embodiments of the present disclosure provide a method and device for storing data. The method comprises: generating a data block corresponding to data to be stored; aligning the data block to a boundary of a tracking unit of a predefined size for validating the data; and storing the aligned data block in at least one storage unit of a storage space, the at least one storage unit having an identical size. The method according to embodiments of the present disclosure can align the data block so as to minimize the waste of storage space and avoid the situation where the rest data cannot be validated due to disappearance of partial data.

Method and device for storing data

Storage blocks are managed. For instance, a set of write parameters and a set of deletion parameters are obtained related to a target storage block. In response to the set of write parameters matching the set of deletion parameters, a first data length is obtained for the target storage block, the first data length being determined in response to receiving a write request for the target storage block. Further, reclaim information is determined related to the target storage block based on the first data length and the set of deletion parameters. It is thus possible to reduce times of scanning the entire object table to determine whether there is an object referring to the storage block, thereby reducing the time consumed by the verification process and improving the reclaiming speed of storage blocks.

Determining reclaim information for a storage block based on data length and matching write and delete parameters

Embodiments of the present disclosure provide a method, a device and a computer program product for data processing. The method comprises in response to data associated with an object being stored in the storage location, generating an entry indicating a first association relationship between the data and a storage location. The method further comprises generating metadata of the object, the metadata indicating a second association relationship between the object and the entry. Further, the method comprises in response to the first association relationship between the data and the storage location being changed, updating the entry independent of the metadata. Embodiments of the present disclosure may avoid the huge cost caused by changing metadata multiple times and reduce the system load and the impacts to the front end load.

Method, device and computer program product for data processing

Embodiments of the present disclosure relate to a method, device and computer program product for data stream processing. The method comprises activating, in response to receiving a starting first predefined tag in a first input data stream from a first data source, a duplicate process of a process by duplicating a state of the process to the duplicate process. The method further comprises processing, by the duplicate process, only a data unit before an ending second predefined tag in a second input data stream from a second data source without interruption of processing of the first and second input data streams by the process. The second data source differs from the first data source. The method further comprises creating a snapshot of the duplicate process for recovery of the process due to failure in response to receiving the ending second predefined tag in the second input data stream.

Method, device and computer program product for data stream processing

Obtaining or facilitating obtaining statistical performance of a storage system is described. For instance, a method comprises: dividing a value range of performance of a storage system into a plurality of adjacent sub-ranges, an upper limit value of each sub-range being a predetermined multiple of a non-zero lower limit value of the sub-range. The method also comprises: determining a distribution of a plurality of measurement values of the performance among the plurality of sub-ranges. The method further comprises: estimating, based on the distribution, a percentile of the plurality of measurement values corresponding to a predetermined percentage to indicate statistical performance of the storage system. As a result, statistical performance indicators of the storage system can be obtained with an acceptable error using a small amount of memory resources.

Obtaining of statistical performance of storage system

Embodiments for accessing data are provided. A method of accessing data comprises: receiving a request to access first data in a storage device, at least a part of data in the storage device being cached in a cache, and index information of the at least a part of data being recorded in an index structure associated with the cache; querying the index structure to determine whether the first data is cached in the cache; and accessing the first data based on a result of the query. Embodiments of the present disclosure can improve data accessing efficiency while saving memory consumption.

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Shanghai, China

Ao Sun