Abstract: A method for reading data from persistent storage. The method includes receiving a client read request for data from a client. The client read request includes a logical address. The method further includes determining a physical address corresponding to the logical address, determining that the physical address is directed to an open block in the persistent storage and determining that the physical address is directed to a last closed word line of the open block. The method further includes, based on these determinations, obtaining at least one read threshold value for the reading from last closed word lines, issuing a control module read request comprising the at least one read threshold value to a storage module that includes the open block, and obtaining the data from the open block using the at least one read threshold value.

Abstract: Embodiments of systems and methods that ensure integrity of data during unexpected power interruption of loss are disclosed. In some embodiments, critical data is saved quickly and efficiently using backup power. Data integrity is ensured even when the reliability of backup power sources is an issue. In some embodiments, by skipping the updating and saving of system data while operating on backup power, significant reduction of time for saving critical data can be achieved. System data can be restored next time the data storage system is restarted. Improvements of data storage system reliability are thereby attained.