Emc IP Holding Company LLC

Dell Products Inc.

Liam Xiongcheng Li

Xinlei Xu

Jian Gao

Lifeng Yang

Ruiyong Jia

Yousheng Liu

Changyu Feng

Hongpo Gao

Geng Han

Jibing Dong

Jamin Jianbin Kang

Lili Chen

Vamsi K Vankamamidi

Huibing Xiao

Baote Zhuo

Tao Xu

Ree Sun

Huadong Li

Jigang Wang

Harriet Zhihui Qiu

Embodiments of the present disclosure relate to methods, devices and computer program products for writing data in a disk array in a storage system. The storage system comprises a disk array. The method comprises: in response to receiving a write request to write new data to a data block in at least one disk array group in a degraded mode within a disk array, reading old data stored in the data block and old parity information stored in a parity block associated with the data block. The method further comprises: determining new parity information associated with the new data based on the old data, the old parity information and the new data. The method further comprises: writing the new data and the new parity information into at least one cache page provided by a cache component in the storage system, the at least one cache page being allocated in a persistent memory in the cache component. In addition, this method further comprises: flushing the new data and the new parity information into the data block and the parity block in the at least one disk array group, respectively.

Methods and devices for writing data into a degraded array using a persistent cache

A method, computer program product, and computing system for determining whether storage space usage on a storage system has reached a predefined threshold of a total storage capacity of the storage system. An out-of-space mode may be initiated on the storage system in response to determining that the storage space usage has reached the predefined threshold of the total storage capacity of the storage system. An amount of free storage capacity for exiting the out-of-space mode may be determined based upon, at least in part, a predefined minimum free storage capacity, a predefined maximum free storage capacity, and the total storage capacity of the storage system.

System and method for managing storage space usage on a storage system

A method and device for managing a storage system comprising multiple storage devices in a first layer and at least one backup storage device in a second layer. In response to receiving a request for writing target data to the storage system, storing the target data to a first portion of storage devices among the multiple storage devices in the first layer; storing a first parity, determined on the basis of a first algorithm, of data in the first portion of storage devices to a second portion of storage devices among the multiple storage devices in the first layer; and storing a second parity, determined on the basis of a second algorithm, of data in the first portion of storage devices to a first backup storage device of the at least one backup storage device in the second layer.

Method and device for managing storage system

Embodiments of the present disclosure provide a method, an apparatus and a computer program product for managing an input/output (I/O). The method comprises, in response to receiving a first I/O request of a first type for a storage device, determining whether there exists at least one credit available to the first type of I/O requests. Each of the at least one credit indicates I/O processing capability reserved by the storage device for the first type of I/O requests. The method further comprises allocating a first credit to the first I/O request based on a result of the determining. The method further comprises performing, by using the first credit, an I/O operation requested by the first I/O request on the storage device. Moreover, the method further comprises, in response to completion of the I/O operation, recycling the first credit for use by a subsequent I/O request. Embodiments of the present disclosure can implement dynamic allocation of I/O processing capability for different types of I/Os.

Method, apparatus and computer program product for managing input/output

Embodiments of the present disclosure relate to methods and apparatuses for data copy. A method comprises receiving, from a client module in a first processing unit, a read request for reading data from a first storage region. The method further comprises, in response to determining from the read request that the data is to be copied, obtaining, from a cache, a first bitmap associated with the first storage region, the first bitmap indicating if the first storage region is filled with zero. The method further comprises, in response to determining from the first bitmap that the first storage region is filled with zero, sending, to the client module, an indication that the data is zero.

Method and apparatus for data copy

Embodiments of the present disclosure provide a method of storage allocation, an electronic device, a storage system and a computer program product. The method of storage allocation includes: obtaining respective wear levels of a plurality of disks associated with a redundant array of independent disks (RAID). The method further includes: determining respective spare extents in disk extents of the plurality of disks based on the obtained wear levels, such that a number of spare extents in a disk is positively correlated with the wear level of the disk. The method also includes: selecting, from disk extents other than the spare extents, a predetermined number of disk extents for creating RAID extents for the RAID, the predetermined number of disk extents being from different disks of the plurality of disks. Through the embodiments of the present disclosure, a life cycle of a disk is prolonged, frequent replacement of worn disks with new disks is avoided, and data loss is reduced.

Method of storage allocation, electronic device, storage system and computer program product

Embodiments include a method performed by a computing device. The method includes (a) receiving a plurality of access requests to access data of a multilayered storage system; (b) in response to determining that a first access request can be served from a top data layer, executing the first access request by accessing the top data layer; (c) in response to determining that a second access request cannot be served from the top data layer, determining whether a current concurrency number of the top data layer is less than a permitted concurrency number (PCN) of the top data layer; and (d) in response to determining that the current concurrency number of the top data layer is not less than the PCN, waiting until the current concurrency number of the top data layer is less than the PCN and then executing the second access request by accessing another data layer below the top layer.

Method, device and computer readable storage media for managing storage system

A storage method and device for a solid-state drive is provided in embodiments of the present disclosure. The method includes: configuring a checkpoint drive and a cache drive; backing up data blocks from a data drive into the checkpoint drive; and in response to the data drives being corrupted, writing into a further data drive part of the data blocks backed up into the checkpoint drive and part of data blocks in the cache drive. The number of required SSD drives can be significantly reduced with the method and device without losing the data restoration capability. In addition, the degrading performance can also be maintained at a relatively high level.

Storage utilizing a distributed cache chain and a checkpoint drive in response to a data drive corruption

Embodiments of the present disclosure relate to methods, devices and computer program products for managing a redundant array of independent disks (RAID). The method comprises: in response to a number of a plurality of disks occupied by the RAID exceeding a first threshold, determining a first number of disk pairs to be disassociated among the plurality of disks, the first number of disk pairs at least comprising a first disk and a second disk associated with each other, and a first extent in the first disk and a second extent in the second disk being included in a same RAID extent of the RAID. The method further comprises determining a third disk for migrating at least one of the first extent and the second extent among the plurality of disks. Besides, the method further comprises migrating the at least one extent to the third disk to disassociate the first disk and the second disk so that a second number of disk pairs associated with each other among the plurality of disks is below a second threshold.

Methods, devices and computer program products for managing a redundant array of independent disks

Implementations of the subject matter described herein provide a storage management method and system. The storage management method comprises: in response to receiving a write request, dividing data to be written into a plurality of data blocks with a predetermined size, the plurality of data blocks having their respective logic block addresses; evenly mapping, based on the logic block addresses, the plurality of data blocks to a plurality of RAID extents of a Redundant Array of Independent Disks (RAID); mapping the plurality of data blocks in the plurality of RAID extents to the disk, so that the plurality of data blocks are distributed in order of size of logic block addresses in the disk.

Processing I/O requests using a redundant array of independent disks (RAID)

Embodiments of the present disclosure relate to a method and device for flushing pages from a solid-state storage device. Specifically, the present disclosure discloses a method of flushing pages from a solid-state storage device comprising: determining a first number based on a period length of one flushing cycle and a period length required for building one flushing transaction, the first number indicating a maximum number of flushing transactions that can be built in the flushing cycle; and flushing pages from the solid-state storage device with an upper limit of the first number in the flushing cycle. The present disclosure also discloses a device for flushing pages from a solid-state storage device and a computer program product for implementing steps of a method of flushing pages from a solid-state storage device.

Flushing pages from solid-state storage device

A method and an apparatus for data storage system are provided. The method comprises: receiving an I/O request from an upper layer, the I/O request including an I/O type identifier; determining an I/O type of the I/O request based on the I/O type identifier; and processing the I/O request based on the determined I/O type. The present disclosure also provides a corresponding apparatus. The method and the apparatus according to the present disclosure can determine a storage policy of corresponding data based on different I/O types to improve the overall system performance.

Method and apparatus for data storage system

Embodiments of the present disclosure relate to a method and a device for cache management. The method includes: in response to receiving a write request for a cache logic unit, determining whether a first cache space of a plurality of cache spaces associated with the cache logic unit is locked; in response to the first cache space being locked, obtaining a second cache space from the plurality of cache spaces, the second cache space being different from the first cache space and being in an unlocked state; and performing, in the second cache space, the write request for the cache logic unit.

Method and device for cache management

A computer-implemented method for establishing a multi-tier flash cache using spare drives. The method includes, in response to receiving an I/O request, determining that there is no free page in a main cache. Having determined that there is no free page in the main cache, the method further includes establishing a secondary cache by selecting at least one spare drive from a plurality of spare drives, flushing data from a cold page in the main cache to the secondary cache, an access frequency of the cold page being lower than a predetermined threshold, and writing data related to the I/O request from a persistent storage device to the cold page.

Method, apparatus and computer readable medium for building multi-tier flash cache by using spare flash drives and clean user data is flushed from main flash cache to one of the spare flash drives that only stores the clean user data, wherein the main flash cache is configured as one or more pairs of flash drives and the one of the spare flash drives is allocated as single drive to secondary flash cache

Embodiments of the present disclosure relate to a method and device for cache management. The method includes: receiving an I/O request associated with a processor kernel; in response to first data that the I/O request is targeted for being missed in a cache, determining whether a first target address of the first data is recorded in one of a plurality of cache history lists; in response to the first target address not being recorded in the plurality of cache history lists, storing, in a first node of a first free cache history list, the first target address and an initial access count of the first target address, the first free cache history list being determined in association with the processor kernel in advance; and adding the first node to a first cache history list associated with the I/O request of the plurality of cache history lists.

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Beijing, China

Liam Xiongcheng Li