Qnap Systems, Inc.

Chin-Tsung Cheng

Jing-Wei Su

Tsung-Han Chiang

A method for deduplication applicable to a file chunked into a plurality of deduplicated chunks is provided and includes: defining a calculation range in the file according to types of the chunks in the file, where the calculation range includes a plurality of consecutive chunks in the file; generating an evaluation value according to the types of the chunks in the calculation range to determine whether to mark the chunks in the calculation range; and re-chunking and deduplicating the marked chunks in the file. A computer-readable medium and a file system corresponding to the method for deduplication are also provided.

Method, computer-readable medium and file system for deduplication utilzing calculation range and re-chunking

A method of prefetching data in a dynamically adjustable amount is executed by: determining a specified number of data blocks according to an averaged data transmission rate and a predetermined fetching index; sending out a data request command to obtain a requested data, wherein the requested data is included in a specified data and consists of the same number of data blocks as the specified number; and receiving and storing the requested data as a prefetch data consisting of the same number of data blocks for prefetch as the specified number. when the specified number is equal to or greater than two, one of the data blocks for prefetch is designated as a launch block for prefetch, and when the launch block for prefetch is read, the fetching index is optionally adjusted according to a predetermined rule.

Data prefetch method in dynamically adjustable amount

A file deduplication processing system is provided. The system deduplicates raw files to generate deduplicated vault files and a descriptor indicating a storage location of each data chunk in the vault files corresponding to the raw files. When receiving a writing request of a write data, the system finds at least one data chunk including old data corresponding to the write data according to the descriptor, loads and recovers the data chunk whose boundary is not overlapped with a boundary of the write data in the vault file comprising the old data corresponding to the write data so as to generate an update data by incorporating the recovered data chunk and the write data, deduplicates the update data to generate a new vault file and stores the same in the chunk store, and updates a content corresponding to each data chunk in the descriptor.

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Taipei, Taiwan

Chin-Tsung Cheng