US Patent 9021339 Data reliability schemes for data storage systems

A data storage system configured to implement a data reliability scheme is disclosed. In one embodiment, a data storage system controller detects uncorrectable errors using intra page parity when data units are read from a set of pages. When an uncorrectable error is detected, the data storage system controller attempts to recover user data using inter page parity without using all data from each page of the set of pages. Recovery of user data can thereby be performed without reading all data from each page. As a result, the amount of time needed to read data can be reduced in some cases and overall data storage system performance can be increased.