Data reconstruction in distributed data storage system with key-based addressing

摘要

In a Distributed Virtual Array data storage system, data chunks making up data containers are stored in a key order in storage devices according to layouts specified in a layout data structure. When any of the storage devices becomes inaccessible, the storage devices iteratively return, in storage order, their stored chunks. Chunks belonging to the same container are identified and, if that container had a chunk in the inaccessible storage device, are used to reconstruct the inaccessible chunk. The chunks of the container are then stored according to an updated layout. The keys are independent of physical storage locations.

主权项

1. A method for recovering data from a plurality of storage devices,
said data being grouped as containers written by at least one writing entity within a corresponding one of a plurality of hosts, each container being identified by a unique key that is independent of physical storage identifiers and comprising a set of data chunks stored in different ones of the plurality of storage devices, said method comprising: detecting inaccessibility of one of the plurality of storage devices in which data chunks are stored; iteratively requesting and receiving data chunks from the data storage devices in which a given container's chunks are stored; for each container having a data chunk stored in the inaccessible storage device, reconstructing from the received data chunks belonging to the same container the corresponding data chunk that had been stored in the inaccessible storage device; and storing the reconstructed data chunk in a different one of the storage devices.