Patent attributes
Described are techniques for processing data. Hash values for the data portions of a logical device are determined. Each data portion has a corresponding one of the hash values. It is determined whether a first of the hash values associated with a first of the data portions is equal to a hash value of an implied data value. If the first hash value is equal to the hash value of the implied data value, first processing is performed including determining whether the first data portion has a current data value equal to the implied data value, and responsive to determining that the first data portion has a current data value equal to the implied data value, performing second processing including updating first metadata for the first data portion to denote that the first data portion has the implied data value. The first data portion is not associated with allocated storage.