Patent ID: 7318072

Claim:
A method for ensuring that rules that prevent premature deletion of data objects stored in a storage system are enforced by servers that store blocks of content that constitute the data objects, the method comprising: associating distinct reference source identifiers with each of a plurality of storage system entities that make reference to blocks of content; associating a set of rules with a data object, the set of rules governing when deletion is allowed and when it is disallowed; computing a hash value based at least in part on both a reference source identifier and information descriptive of or used by the set of rules; and communicating information which allows the hash value to be computed, to a server that stores a block of content that is a constituent of the data object; wherein the communicated information is part of a request to delete the block of content; and wherein when deletion of the data object is disallowed, modification of the content of the data object is also disallowed.