Patent ID: 8583866

Claim:
A write-back distributed data storage system for maintaining data storage reliability, comprising: multiple nodes, each node comprising a data managing hardware processor and an array of failure independent data storage devices; the nodes configured for storing information as a stripe including a collection of data strips and associated parity strips, the stripe distributed across data and parity nodes, each data node configured for maintaining an associated data strip holding a first copy of data, and each parity node configured for maintaining a parity strip holding a parity for the collection of data strips; and a driver node further configured for initiating a full-stripe-write parity update protocol for maintaining parity coherency in conjunction with other nodes comprising data and parity nodes, by determining parity directly by computing new parity values for all data strips of a stripe from fast write data in order to keep the relevant parity strips coherent, such that any node may function as a driver node, wherein: each parity held by a parity strip is calculated based on a different parity calculation formula for each parity; upon detecting new data, a host writes new data to one or more strips in a stripe; and the driver node computes new parity if the driver node is a parity node, and sends a commit message to another node in a predefined message order sequence, wherein each respective node receiving a commit message computes new parity if that respective node is a parity node, and sends a commit message to a next node in the predefined message order sequence unless that respective node is a last node in the predetermined message order sequence.