Writing data in a distributed data storage system

A non-transitory computer-readable storage medium containing instructions for writing data, the data including one or more storage units, the instructions for controlling a computer system to perform operations comprising:

• receiving a write request, the write request including the data and a client address at which to store the data;
• segmenting the data into the one or more storage units;
• computing a storage unit identifier for each of the one or more storage units, wherein the storage unit identifier for each storage unit uniquely identifies content of the storage unit;
• determining, by a metadata server, a mapping between each storage unit identifier to two or more block servers;
• replicating, by the metadata server, the mapping to one or more other metadata servers to provide the mapping in case of failure of the metadata server;
• and
• for each of the one or more storage units, sending the storage unit and the corresponding storage unit identifier to each of the two or more block servers based upon the mapping, wherein each block server stores the storage unit and information on where the storage unit is stored on the block server for the storage unit identifier, and wherein multiple client addresses associated with a storage unit with a same storage unit identifier are mapped to a single storage unit stored in a storage medium for a block server.

A system comprising:

• a metadata server comprising a processor and a non-transitory machine-readable medium having stored therein instructions, which when executed by the processor cause the metadata server to:
• receive a write request, the write request including the data and a client address at which to store the data;
• segment the data into the one or more storage units;
• compute a storage unit identifier for each of the one or more storage units, wherein the storage unit identifier for each storage unit uniquely identifies content of the storage unit;
• determine a mapping between each storage unit identifier to two or more block servers;
• replicate the mapping to one or more other metadata servers to provide the mapping in case of failure of the metadata server;
• and
• for each of the one or more storage units, send the storage unit and the corresponding storage unit identifier to each of the two or more block servers based upon the mapping, and wherein multiple client addresses associated with a storage unit with a same storage unit identifier are mapped to a single storage unit stored in a storage medium for a block server;
• and
• two or more block servers each configured to:
• store the storage unit and information on where the storage unit is stored on the block server for the storage unit identifier.