Emc IP Holding Company LLC

Xiongcheng Li

Xinlei Xu

Jian Gao

Lifeng Yang

Changyu Feng

Ruiyong Jia

Geng Han

Yousheng Liu

Jibing Dong

Jianbin Kang

Hongpo Gao

Sihang Xia

Shaoqin Gong

Lei Sun

Xiaobo Zhang

Yongjun Wu

John V Harvey

Vamsi K Vankamamidi

Thomas Earl Linnell

Sheng Wang

Haiying Tang

Rongrong Shang

Henry Austin Spang, Iv

Zhenhua Zhao

Lei Xue

Charles H Hopkins

Peng Xie

Tianshu Sun

Ping Ge

Techniques for managing metadata storage units involve: in response to receiving, from a client, a request for allocating a target number of metadata storage units, determining a first number of available metadata storage units remaining in a metadata storage space of a storage system after the allocation is performed; and if the first number is not less than a reserved number, allocating the target number of metadata storage units from the metadata storage space for the client to use, wherein the reserved number is associated with a usage condition of the metadata storage units in the storage system. Accordingly, such techniques can effectively manage metadata and improve the performance of a system.

Method, electronic equipment and computer program product for managing metadata storage unit

Techniques provide for managing storage devices. Such techniques involve: combining storage devices in a redundant array of independent disks into a group of storage devices in an order of physical capacities of the storage devices; determining a first number of sets of storage devices based on a number of storage devices in the group and a threshold number of storage devices to be divided into each of the sets; and dividing, based on a configuration of the redundant array of independent disks, the group of storage devices into the first number of sets of storage devices, to optimize an effective capacity of the redundant array of independent disks.

Method for managing storage devices, electronic device and computer-readable medium

Techniques involve: writing, when a first disk for dirty page storage has a failure, a first target page description generated by a first node and associated with a first set of target dirty pages of the first node and a second set of target dirty pages of a second node to a first page description storage layer for the first node in a second disk; writing a second target page description generated by the second node and associated with the first set of target dirty pages and the second set of target dirty pages to a second page description storage layer for the second node in the second disk; and restoring, when the failure has been eliminated, the first set of target dirty pages and the second set of target dirty pages in the first disk based on at least one of the descriptions.

Method, electronic device and computer program product for storage management

The present disclosure relates to a method, a device, and a computer program product for managing a storage system. The storage system includes a first control node, a second control node, and a persistent storage device, the first control node being in an activated state, and the second control node being in a state of transfer from a non-activated state to an activated state. A method includes: loading a first list of page descriptors of the storage system to the second control node to generate a second list of page descriptors at the second control node, the first list including a portion of multiple page descriptors of the storage system that has been modified but has not been flushed to the persistent storage device; receiving a synchronization message from the first control node that indicates that the first list has been modified by the first control node; and updating the second list at the second control node based on the synchronization message. Further, a corresponding device and a corresponding program product are provided. With the example implementations of the present disclosure, the start performance of the control nodes in the storage system can be improved.

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

Embodiments of the present disclosure relate to a method and apparatus for managing cache. The method comprises determining a cache flush time period of the cache for a lower-layer storage device associated with the cache. The method further comprises: in response to a length of the cache flush time period being longer than a threshold length of time, in response to receiving a write request, determining whether data associated with the write request has been stored into the cache. The method further comprises: in response to a miss of the data in the cache, storing the write request and the data in the cache without returning a write completion message for the write request.

Method and devices for managing cache

Techniques read data. Such techniques involve: in response to receiving a read request from the user for data on a physical data block, determining whether there is data state information corresponding to the physical data block. The data state information may include a plurality of units for respectively indicating availability of data stored in a plurality of sub-blocks of the physical data block. Such techniques further involve: in response to determining that there is data state information, selecting a target sub-block from the plurality of sub-blocks of the physical storage block based on the data state information. Such techniques further involve: providing the user with data stored in the target sub-block. Such techniques are capable of determining the availability of data at a finer granularity.

Reading data in sub-blocks using data state information

Techniques involve managing a storage space. In response to receiving an allocation request for allocating a storage space, a storage space size and a slice size are obtained. A first storage system and a second storage system are selected from multiple storage systems, the first storage system and the second storage system includes a first storage device group and a second storage device group respectively, and the first storage device group does not overlap the second storage device group. A first slice group and a second slice group is obtained from the first storage system and the second storage system respectively, on the basis of the size of the storage space and the size of the slice. A user storage system is built at least on the basis of the first slice group and the second slice group, so as to respond to the allocation request.

Method, apparatus, and computer program product for managing storage space provided across multiple storage systems

Techniques manage a cache. Such techniques involve creating a primary cache by a cache management module in a storage system. Such techniques further involve: in response to the primary cache being created, sending a first request to a hardware management module to obtain first information about a first virtual disk. Such techniques further involve: in response to receiving the first information from the hardware management module, creating a secondary cache using the first virtual disk. Such techniques further involve: in response to an available capacity of the primary cache being below a predetermined threshold, flushing at least one cache page in the primary cache to the secondary cache. In certain techniques, it is possible to use spare extents in the disk array to create the secondary cache to increase a total capacity of the cache in the system, thereby improving the access performance of the system.

Method, apparatus and computer program product for managing cache

A method of managing operation of a data storage system (DSS) is provided. The method includes (a) reserving space within a dedicated metadata storage region (DMSR); (b) in response to determining that accommodating a storage request requires use of the reserved space, entering a restricted write mode; (c) while operating in the restricted write mode, using the reserved space in a process that frees space within the DMSR outside the reserved space; and (d) exiting the restricted mode in response to freeing space within the DMSR outside the reserved space. An apparatus, system, and computer program product for performing a similar method are also provided.

Managing operation of a data storage system with reservation of metadata space

Techniques process and manage a storage unit access. In accordance with such a technique, a data access request which is from a host system and for a first storage unit in the first storage system is received, wherein the first storage unit is a secondary storage unit; and the data access request is forwarded to a second storage unit in a second storage system associated with the first storage unit via a redirection link from the first storage system to the second storage system, wherein the second storage unit is a primary storage unit. Through such techniques, the host system can be allowed to send a data access request for the secondary storage unit, so that the host system does not need to resend the data access request, thereby reducing delay and interruption caused by such requests.

Methods, apparatuses and computer program products for processing and managing storage unit access

A technique involves: in response to receiving a first request for adjusting a first width of a disk array to a second width, obtaining, based on source identification information of a source stripe group in the disk array in the first request, source block identification information of a source block associated with the source stripe group. The technique further involves: determining destination identification information of a destination stripe group associated with the second width for storing data. The technique further involves: storing, based on the source identification information and the destination identification information, source data and metadata for the source data from the source block into a destination block of the destination stripe group, the metadata including node identification information for accessing nodes of the source block. The technique further involves: adjusting the node to access the destination block based on the node identification information.

Method, device and computer program product for data processing

Techniques manage a redundant array of independent disks. Such techniques involve: obtaining information on a wear level associated with each of a plurality of disks; selecting, based on the information on the wear level, a group of disks from the plurality of disks, a difference between the wear levels of any two of the group of disks being below a predetermined threshold; and creating a RAID with extents from the selected group of disks. Such techniques can sufficiently utilize the wear level to balance the data storage distribution among redundant arrays of independent disks, thereby enabling efficient management of redundant arrays of independent disks.

Method, electronic device and computer program product for managing redundant arrays of independent disks

Techniques detect incomplete write of data. The techniques involve obtaining metadata associated with a sector in a parity disk of a Redundancy Array of Independent Disks (RAID), wherein the metadata includes a sequence stamp and a partial write flag, the sequence stamp changing with a write operation on a stripe to which the sector belongs, and the partial write flag indicating whether the stripe is partially written. The techniques further involve determining whether incomplete write of data is present in the RAID based on the metadata, and the techniques further involve in response to determining the incomplete write of the data being present in the RAID, rebuilding at least one disk in the RAID. By adding a sequence stamp and a partial write flag in the metadata of the sector of the RAID, incomplete write of data can be detected more accurately, thereby improving the reliability of RAID.

Method, device and computer program product for detecting incomplete write of data

A storage system is associated with at least one part of multiple storage devices in a resource pool, a part of a storage space in a storage device being inaccessible to the storage system. Techniques involve: identifying an extent within the part of the storage space in the storage device as a free extent; selecting a group of storage devices each with a free extent from the multiple storage devices in response to determining a virtual address range in the storage system as specified by an access request is inaccessible; mapping the virtual address range to a physical address range of the free extents in the group of storage devices; and allocating a storage space specified by the physical address range to the storage system. Therefore, the expansion of the resource pool can be implemented more conveniently and rapidly, and performance of the storage system can be improved.

Method, apparatus and computer program product for managing storage system

Various techniques manage a storage system. Such techniques involve: in response to detecting that a first request of a plurality of requests initiated for a bulk request is completed, determining a response time length for the first request, the bulk request being used to migrate data from a first storage device to a second storage device, each request of the plurality of requests being used to read data from the first storage device and write data to the second storage device; determining an average response time length of the completed requests of the plurality of requests based at least in part on the response time length for the first request; and updating the number of the plurality of requests initiated for the bulk request based on the average response time length.

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Beijing, China

Xiongcheng Li