Low-overhead deduplication within a block-based data storage

摘要

A write-data hash value corresponding to a block of write data is generated within a deduplicating data storage system. A block of lookup table entries is retrieved from a location in a lookup table stored within a block-based storage medium, the lookup table location being indicated by a first portion of the write-data hash value and each lookup table entry including a pointer to a respective stored data volume, a portion of a hash value that corresponds to the stored data volume, and a reference count indicating a quantity of references to the stored data volume. A second portion of the write-data hash value is compared to the portions of the hash values within the block of lookup table entries, and the reference count is incremented within one of the lookup table entries for which the portion of the hash value is determined to match the second portion of the write-data hash value.

主权项

1. A method of operation within a deduplicating data storage system, the method comprising:
generating a write-data hash value that corresponds to a block of write data; retrieving, from a lookup table stored within a block-based storage medium, a block of lookup table entries from a location within the lookup table indicated by a first portion of the write-data hash value, each lookup table entry including a pointer to a respective stored data volume, a portion of a hash value that corresponds to the stored data volume, and a reference count indicating a quantity of references to the stored data volume; comparing a second portion of the write-data hash value to the portions of the hash values within the block of lookup table entries; and incrementing the reference count within a first one of the lookup table entries for which the portion of the hash value therein is determined to match the second portion of the write-data hash value.