Method and system of retrieving data in a data file

A method for retrieving at least a portion of a second derived virtual data file, the second derived virtual data file being derived from a first data file based on a first data file virtualization policy, the method being implemented by a computer system, the first data file being stored in a storage device in communication with the computer system, the method comprising:

• receiving, by the computer system from a client computer system in communication with the computer system, a request for the at least a portion of the second derived virtual data file, the request including a virtual offset of the at least a portion of the second derived virtual data file and a size of the at least a portion of the second derived virtual data file;
• computing, by the computer system, a data offset and a size of at least a portion of the first data file to derive the requested at least a portion of the second derived virtual data file;
• reading, by the computer system, data from the first data file based on the computed data offset and size of the at least a portion of the first data file;
• generating, by the computer system, the requested at least a portion of the second derived data file using information in the first data file virtualization policy and the read data from the first data file;
• and
• transmitting, by the computer system to the client computer system, the requested at least a portion of the second derived virtual data file.

A system for retrieving at least a portion of a first data file stored in a storage device in communication with a computer system, the computer system being configured to:

• receive from a client computer system in communication with the computer system, a request for the at least a portion of the first data file, the request including a start of the at least a portion of the first data file and a size of the at least a portion of the first data file;
• compute a data offset that is aligned to an integer multiple of a block size of the storage device and nearest to the start of the at least a portion of the first data file;
• compute a byte-range that is an integer multiple of the block size of the storage device, the byte-range being greater than and encompasses the size of the at least a portion of the first data file;
• read data within the byte-range and transferring the data within the byte-range starting at the data offset into memory of the computer system;
• and
• transmit to a client computer system the at least a portion of the first data file from the memory starting at an offset relative to the data offset that is aligned to an integer multiple of the block size of the storage device.

A system for retrieving at least a portion of a second derived data file, the second derived virtual data file being derived from a first data file based on a first data file virtualization policy, the first data file being stored in a storage device in communication with a computer system, the computer system being configured to:

• receive from a client computer system in communication with the computer system, a request for the at least a portion of the second derived virtual data file, the request including a virtual offset of the at least a portion of the second derived virtual data file and a size of the at least a portion of the second derived virtual data file;
• compute a data offset and a size of at least a portion of the first data file to derive the requested at least a portion of the second derived virtual data file;
• read data from the first data file based on the computed data offset and size of the at least a portion of the first data file;
• generate the requested at least a portion of the second derived data file using information in the first data file virtualization policy and the read data from the first data file;
• and
• transmit to the client computer system the requested at least a portion of the second derived virtual data file.