Emc IP Holding Company LLC

Emc Corporation

Gang Xie

Junping Zhao

Philippe Armangau

Wei Qi

Fenghao Zhang

Jialin Yang

Kevin Xu

Fenghua Hu

Ivan Bassov

Yining Si

A method is used in managing deletion of replicas of files. A request is received to delete a replica of a file of a file system. The replica of the file represents a state of the file at a particular prior point in time. The replica is associated with a group including a set of replicas of the file system identified for deletion. Each replica is deleted in the group concurrently by using a delete marker. The delete marker is used for tracking deletion of each replica in the group.

Managing deletion of replicas of files

A method is used in managing deletion of replicas of files. A request to delete a set of replicas of a file of a file system is received. A replica of the file represents a state of the file at a particular prior point in time. A destination replica is identified. A set of file system blocks shared between a replica of the set of replicas and the destination replica is de-allocated by updating metadata of the destination replica. File system blocks associated with the set of replicas are de-allocated. A subset of the file system blocks are de-allocated concurrently.

Embodiments of the present invention relate to a method, apparatus and computer product for managing memory space. In one aspect of the present invention, there is provided a method for managing memory space that is organized into pages, the pages being divided into a plurality of page sets, each page set being associated with one of a plurality of upper-layer systems, by: performing state monitoring to the plurality of upper-layer systems to assign priorities to the plurality of upper-layer systems; and determining an order of releasing the pages of the memory space based on the priorities of the plurality of upper-layer systems with the page sets as units. Other aspects and embodiments of invention are also disclosed.

Method and apparatus for managing memory space

A method is used in managing processing tasks in storage systems. A set of tasks is received for processing. A type of the set of tasks is identified. Based on the type of the set of tasks, a determination is made as to whether to add data objects associated with the set of tasks to a used object list managed in conjunction of a cache of the system for accessing the data objects associated with the set of tasks. The cache is configured to store the data objects of the storage system. A portion of a memory of the storage system is reserved as the cache.

Managing processing tasks in storage systems

A technique manages access to a B-tree structure within a data storage apparatus. The B-tree structure maintains mappings of data blocks of a file system to data blocks of a snapshot storage area. The technique involves imposing a lock on the B-tree structure in response to a snapshot operation which copies a contiguous range of file system data blocks to a set of snapshot data blocks to save primary data of the file system as snapshot data. The technique further involves inserting multiple objects into the B-tree structure while the lock is imposed, each object including a key value which (i) identifies a respective file system data block of the contiguous range and (ii) operates as a search key to facilitate searching of nodes of the B-tree structure. The technique further involves releasing the lock imposed on the B-tree structure after the objects have been inserted into the B-tree structure.

Efficient extent-based B-tree insertion

A technique performs a write operation. The technique involves receiving, after a snapshot of a file system is taken, a write instruction to write new data to a particular portion of the file system. The technique further involves includes reading, in response to the write instruction, metadata to determine whether the new data is a first update of the particular portion since the snapshot was taken. The metadata identifies portions of the file system which have changed since the snapshot was taken. The technique further involves, when the new data is a first update of the particular portion since the snapshot was taken, copying the original data from cache memory (i.e., from the file system buffer cache) to snapshot storage (i.e., to a dedicated save area) and, after the original data is copied, updating the original data in the cache memory with the new data.

Growing community of inventors

Beijing, China

Gang Xie