US Patent 7949630 Storage of data addresses with hashes in backup systems

Seek operations required to perform restore processes at an HFS server are reduced by storing storage addresses of data associated with hash values included in recipes with the recipes. In a typical embodiment, an HFS server receives a recipe for entry into a hash file system and performs a reference check on the recipe to avoid data corruption. This includes using hash values of the associated data to lookup storage addresses for the associated data in corresponding index stripes. The identified storage addresses can be appended to/stored with the recipe when the recipe is stored by the HFS server. Later during a restore process, retrieval of the recipe also retrieves the storage addresses without having to look up the storage addresses in the corresponding index stripes. Consequently, seek operations during restore can be cut in half and the speed of performing the restore can be doubled.