Data error detection and correction using hash values

摘要

The subject disclosure is directed towards a data storage service that uses hash values, such as substantially collision-free hash values, to maintain data integrity. These hash values are persisted in the form of mappings corresponding to data blocks in one or more data stores. If a data error is detected, these mappings allow the data storage service to search the one or more data stores for data blocks having matching hash values. If a data block is found that corresponds to a hash value for a corrupted or lost data block, the data storage service uses that data block to repair the corrupted or lost data block.

主权项

1. A method for maintaining data integrity in a data storage service, the method comprising:
accessing mappings between hash values and data blocks; comparing a first hash value of a corrupted data block with the mappings; upon determining that a matching hash value for the first hash value does not exist, modifying the corrupted data block; performing a hash on the modified corrupted data block to produce a second hash value; comparing the second hash value with the mappings; and if the mappings comprise a matching hash value for the second hash value, repairing at least a portion of the corrupted data block using applicable data from a data block that corresponds to the matching hash value.