Patent ID: 6691137
Filing Date: 2004-02-10
Classification: G06F,Y10S

Abstract:
A method of managing a data storage system having a cache and a base storage, the method comprising operations of:responsive to each receipt of a data object for storage in the data storage system, obtaining a unique anywhere token and storing the anywhere token in a token database in association with said data object; responsive to receiving an update to a data object contained in the data storage system, obtaining an updated anywhere token and storing the updated anywhere token in the token database in association with that data object so as to replace any anywhere token previously stored in association with that data object; performing storage management operations, comprising: responsive to storage of a data object in the cache, storing the data object's most recent anywhere token in the token database in association with that data object; responsive to storage of a data object in the base storage, storing the data object's most recent anywhere token in the token database in association with that data object, and also establishing a base token replicating the data object's most recent anywhere token and storing the base token in the token database in association with that data object; in the base storage, recording contents of base tokens corresponding to a first group of data objects, the first group including at least those data object contained in the base storage; responsive to a cache failure, ceasing the storage management operations; and responsive to resumption of cache operation, performing operations comprising: identifying any data objects missing from the cache as a result of the cache failure; for each data object missing from the cache, obtaining the data object's base token, creating a replacement anywhere token by replicating the base token, and establishing a replacement token database associating the data object with the base token and the replacement anywhere token; utilizing the replacement token database in substitution for the previous token database.