Emc IP Holding Company LLC

Denny Dengyu Wang

Lester Zhang

Chen Gong

Jian Gao

Joe Jian Liu

Junping Zhao

Wei Cui

Walter Wang

Geng Han

Ruiyong Jia

Leon Zhang

Donglei Wang

Bean Bin Zhao

Seven Duan

Umer Najem Toor

Ted Guangkai Zhang

Tony Fuchuan Xu

A computer-implemented method includes caching data from a persistent storage device into a cache. The method also includes caching a physical address and a logical address of the data in the persistent storage device into the cache. The method further includes in response to receiving an access request for the data, accessing the data cached in the cache using at least one of the physical address and the logical address. The embodiments of the present disclosure also provide an electronic apparatus and a computer program product.

Method and device for optimization of data caching

Various embodiments of the present disclosure generally relate to a method and an electronic device for reading data. Specifically, the method comprises receiving a request for reading the target data, and in response to the request, searching for the target data by searching a data index generated in a cache for reading data. The method further comprises in response to the target data being found, providing the target data. A corresponding system, device and computer program product are also provided.

Method and electronic device for accessing data

A method, apparatus, and computer program product for reclaiming one or more chunks in a snapshot storage space, are disclosed. The method comprises detecting one or more unused chunks in the snapshot storage space in response to a predefined trigger event, and reclaiming one or more detected unused chunks by providing the one or more detected unused chunks to a storage pool for reuse. One or more unused chunks may be detected by scanning a first mapping table that records a storage state of a plurality of chunks in the snapshot storage space, and a determination made whether the one or more detected unused chunks have been reclaimed. If the one or more detected unused chunks have not been reclaimed, the one or more detected unused chunks may be provided to the storage pool and a second mapping table updated to record a reclaiming state of the one or more unused chunks. A new snapshot may be stored using a chunk in the snapshot storage space that has not been used and has not been reclaimed yet.

Method and apparatus for reclaiming memory blocks in snapshot storage space

Embodiments of the present disclosure generally relate to a method and device for managing caches. In particular, the method may include in response to receiving a request to write data to the cache, determining the amount of data to be written. The method may further include in response to the amount of the data exceeding a threshold amount, skipping writing data to the cache and writing the data to a lower level storage of the cache. Corresponding systems, apparatus and computer program products are also provided.

Method and device for managing caches

The embodiments of the present disclosure provide a computer-implemented method. The method includes caching data from a persistent storage device into a cache. The method also includes caching a physical address and a logical address of the data in the persistent storage device into the cache. The method further includes in response to receiving an access request for the data, accessing the data cached in the cache using at least one of the physical address and the logical address. The embodiments of the present disclosure also provide an electronic apparatus and a computer program product.

Embodiments of the present disclosure relate to a method and apparatus for locking a file in a memory. The method comprises enabling a thread to obtain a mixed lock of a file. The method further comprises, in response to enabling the thread to obtain the mixed lock, enabling a further thread to obtain a shared lock of the file, and prevent the further thread from obtaining the exclusive lock or mixed lock of the file. By adding a new mixed lock to a traditional read and write lock, embodiments of the present disclosure improve concurrent access performance of the file system.

Method and apparatus for locking file in memory

Various embodiments of the present invention provide a method and apparatus for reusing a storage block of a file system. The file system is based on a thin provision storage configuration and shares a storage pool with a further file system. The method comprises detecting an unused storage block in a storage space of the file system in response to a predefined trigger event. The method further comprises in response to an unused storage block being detected in the storage space, providing the unused storage block to the storage pool for being reused. According to various embodiments of the present invention, effective utilization of the storage space of the storage pool is achieved.

Reusing storage blocks of a file system

Described are techniques for processing capacity-related event occurrence. A first occurrence is determined for of any of a low threshold event and an out of space event for a first storage pool. A set of one or more virtually provisioned logical devices has physical storage provisioned from the first storage pool and physical storage for a file system is provisioned from the set of one or more virtually provisioned logical devices. First processing is performed responsive to determining the first occurrence of any of the low threshold event and the out of space event for the first storage pool. The first processing includes performing processing to that protects the file system.

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Beijing, China

Denny Dengyu Wang