Abstract: A method for executing a write request in a clustered computing environment, comprising a plurality of computers connected in a network, including at least one client computer accessing data blocks stored on a first storage device of a shared aggregated pool of storage devices. Data blocks stored on the first storage device are linked to data blocks stored on at least one second storage device of the pool by error recovery data stored on a third storage device of the pool. When a client computer sends a write request to the first storage device for a new data block to be stored at an address on the first storage device, the new data block is written at the address on the first storage device. New error recovery data is calculated for the data block and is written to the third storage device.

Abstract: A method for retrieving and modifying data elements on a shared medium following request from multiple client computers, such that data retrieval transactions on a data element, originating from one or more clients, are not compromised by data update transactions on the same data element originating from other clients. The shared medium controller receives from multiple clients transaction requests for reading or writing a data element stored on the shared medium. The transactions requests are added to an execution queue in order. All read transaction requests are then retrieved and executed in parallel, up to a write transaction request on the data element. The write transaction request is then executed while all incoming read transaction requests for the same data element are queued until the write transaction request is completed.

Abstract: The data storage system comprises a scalable number of routing processors (RPs) through which clients of a network communicate. The storage system also includes a scalable number of storage processors (SPs) connected to a scalable number of storage units (SUs). This data storage system provides a new and hybrid approach which lies in between conventional NAS and SAN environments. It creates a unified and scalable storage pool accessible through a single consistent directory without the need for a metadata controller (MDC). There is thus no table lookup at a central node and no single point of failure. It allows a dissociation of the relationship between the physical path and the actual location where the data objects are stored.