Data storage method, device and distributed network storage system

A data storage device comprising:

• a data block device which splits a file of size M into k blocks, wherein M is a measure of an amount of data in the file and k is a positive integer and is the smallest number of nodes required to reconstruct the file, where each block is of size M/k;
• a first block allocation device which distributes the k blocks into k first nodes in a distributed network storage system;
• a first encoding device which constructs n-k independent blocks via linear coding employing a Maximum-Distance Separable (MDS) code from the k blocks and satisfying a property that arbitrary k of the n encoded blocks can reconstruct the file;
• a second block allocation device which distributes n-k encoding blocks into n-k second storage nodes wherein, n, k are both positive integers, and satisfy n>k, and n is the number of total nodes in distributed network storage system, while k is the least number of nodes needed to reconstruct the file;
• and
• a node recovery device which determines that nodes have failed and that no more than n-k first and second nodes have failed and recovers data stored in failed first and second nodes through linear encoding via at least k intact nodes, wherein data in the failed first nodes is exactly regenerated with interference alignment and wherein data in the failed second nodes is regenerated maintaining a MDS code property.